Endometriosis is an estrogen-dependent condition affecting 2-10% of general population of women. This illness may bring on strong pain of various kinds and is recognised as a cause in some cases of infertility. It is thus desired to find a surgical technique for treating endometriosis which allows both the relief of pain and the preservation of fertility. The primary aim of the presented paper is the assessment of therapeutic effects of ablative techniques, including CO2 laser ablation in endometriosis and related pain treatment, with particular focus on how such treatment affects the ovarian reserve.The study covered patients with preliminary diagnoses of pelvic endometriosis, who were scheduled for laparoscopic surgery, in whom the ovarian reserves were assessed and had been subject to a survey evaluating the occurrence and intensity of various kinds of pain possibly related to endometriosis. Patients were operated upon with use of various laparoscopic techniques. Some were operated upon with a CO2 laser or using electroablation. After 3 and 6 months they were examined for changes in pain intensity. Another group of patients were operated upon with a combination of the classical laparoscopic surgical method of removal and the above-mentioned ablative techniques. In these patients, changes in the ovarian reserves were examined after 3 and 6 months too.In all examinations, the degree of advancement of endometric changes was assessed intra-operatively according to the rASRM scale (revised Classification of Endometriosis of the American Society for Reproductive Medicine), by which the analysis of the dependence between the degree of endometriosis advancement and the size of the initial ovarian reserve was carried out.In article no. 1 and no. 3, the ovarian reserve was assessed using biophysical and biochemical parameters. In article no. 1 the initial, pre-surgery ovarian reserve was analysed, thus the AFC (antral follicle count) was assessed, as well as the FSH level in 1-3 day of cycle. In article no. 3, as well as the above-mentioned parameters, pre- and post-surgery BOV (basal ovarian volume) was analysed, and the possibility of relapse was assessed using ultrasound scanning. In article no. 2 a survey with a scale (numerically rated) of 11 degrees of pain intensity was used to analyse changes in feeling various types of pain. The level of pain intensity was examined for pain during menstruation (dysmenorrhea), pain during intercourse (dyspareunia), during urination (dysuria), disorder of and pain during defecation (dyschesis) and pain in the pelvis minor not connected with the menstrual cycle (PPS). The sample group in article no. 1 was 39 patients, in no.2 it was 48, and in no.3 it was 58. ; The study has not found a statistically significant correlation between the degree of endometriosis advancement according to the rASRM scale and the level of ovarian reserve, assessed by analysis of AFC and FSH levels.In treatment of pain related to endometriosis, mixed results were found about reduction in the various different pain categories. Satisfactory results for both methods were achieved in the treatment of pain during menstruation (p-0.025 for CO2 laser ablation and p-0.004 for electroablation), in the follow-up after 6 months. CO2 laser ablation was assessed as ineffective for the treatment of long-term dyschesis (intensity of pain after 6 months: p-0.018) and dyspareunia (p-0.016 in follow-up after 6 months, despite an initial improvement after 3 months: p-0.035). The increase of dyschesis intensification in this group correlated to the appearance of endometric relapses shown with ultrasound during the follow-up examination after 6 months (p-0.002). Intensification of dyspareunia after 6 months was also observed in group after electroablation (p-0.032).CO2 laser ablation and electroablation in combination with the laparoscopic surgical removal of ovarian endometriosis (excisional capsule-EC) proved effective in the preservation of AFC. The BOV levels declined significantly in the group treated with EC/electroablation (p-0.0012 after 3 months; p-0.001 after 6 months). The FSH level dropped significantly after 3 months only in the EC/electroablation group (p-0.023).After 6 months, ultrasound showed a high percentage (39%) of relapses for the group treated with EC/ CO2 laser ablation, while in the EC/electroablation group it was 17%. ; It has been shown that ablative techniques brought the envisaged therapeutic effect in the treatment of only some types of pain related to pelvic endometriosis. Neither studied technique had a long-term therapeutic effect for pain connected with DIE (deep infiltrating endometriosis), showing that the low invasiveness of the mentioned ablative techniques is ineffective in the treatment of deeply-infiltrating endometriosis and should not be used as standard. This statement particularly concerns CO2 laser ablation after which ultrasound indicated a high number of endometric relapses, and for which a correlation between their occurrence and the intensification of dyschesis symptoms was observed. Application of the discussed methods in treatment of menstrual pain, which is primarily associated with the occurrence of superficial, and possibly also ovarian endometriosis, could be considered.CO2 laser ablation and electroablation techniques find application in ovarian endometriosis treatment in respect to ovarian reserve preservation. The combination of ablative methods with the recommended classical technique of cyst removal kept the AFC at an unchanged level, which is the most important indication of ovarian reserve. In addition, no increase of FSH was noted. Any increase could mean a diminished ovarian reserve. It was shown that use of EC/electroablation causes a lower BOV, while EC/CO2 laser ablation resulted in a higher number of relapses, as found by follow up ultrasound examination, and a lower percentage of pregnancies. The electrical power used during bipolar electroablation (60-70 Wat) is likely to be too high and causes greater destruction of ovarian tissue than with CO2 laser ablation. Whilst the power of the laser beam (10-20 Wat) allows for better precision and less destruction of the ovarian cortex, it is too weak to remove endometrial cyst tissue completely which results in a high number of relapses. Therefore it seems advisable to modify the parameters of ablative techniques in order to preserve the ovarian reserve and diminish the relapse percentage.These results lead to the conclusion that none of the studied methods may be seen as optimal and application of these methods should be chosen individually.