Aims: 1). The paper aimed at assessing the learning curve for intraoperative RLN neuromonitoring. 2). And to examine whether the use of IONM in thyroid reoperations can reduce the prevalence of RLN injury.Material and methods: Ad 1). The prospective analysis included 100 consecutive thyroid operations performed by a single surgeon during implementation of RLN neuromonitoring in a district surgical ward in Staszów. RLN neuromonitoring was performed in keeping with the recommendations of the International Neural Monitoring Study Group. The outcomes of initial 50 procedures (Group I: 08/2012-07/2013) were compared with the results of subsequent 50 operations (Group II: 08/2013-07/2014). The evaluation included demographic and intraoperative data along with predictive value of the method and complications. Ad 2). This was a retrospective cohort study of patients who underwent thyroid reoperations at clinical department of surgery in Kraków with intraoperative neuromonitoring versus with RLN visualization, but without neuromonitoring. The database of thyroid surgery was searched for eligible patients (treated in the years 1993–2012). The primary outcomes were transient and permanent RLN injury. Laryngoscopy was used to evaluate and follow RLN injury.Results: Ad 1). In Group II as compared to Group I, a significant reduction of operative time was noted (102.1±19.4 vs. 109.9±19.0; p=0.045), along with an increased percentage of identified RLNs (99.0% vs. 89.2%; p=0.006), a decreased percentage of correction-requiring technical errors (8.0% vs. 24.0%; p=0.029), an improved negative predictive (99.0% vs. 89.3%; p<0.001) and positive value (75.0% vs., 55.6%; p<0.001), as well as a decreased percentage of RLN injuries (3.0% vs. 14.0%; p=0.006). Ad 2). The study group comprised 854 patients (139 men, 715 women) operated for recurrent goiter (n = 576), recurrent hyperthyroidism (n = 36), completion thyroidectomy for cancer (n = 194) or recurrent thyroid cancer (n = 48), including 472 bilateral and 382 unilateral reoperations; 1,326 nerves at risk (NAR). A group of 306 patients (500 NAR) underwent reoperations with intraoperative neuromonitoring and 548 patients (826 NAR) had reoperations with RLN visualization, but without neuromonitoring. Transient and permanent RLN injuries were found respectively in 13 (2.6 %) and 7 (1.4 %) nerves with neuromonitoring versus 52 (6.3 %) and 20 (2.4 %) nerves without neuromonitoring (p = 0.003 and p = 0.202, respectively).Conclusions: Ad 1). Mastering the technique of intraoperative RLN neuromonitoring in thyroid surgery requires the surgeon to perform independently approximately 50 monitored procedures, what allows for achieving the predictive value of the method that is comparable to outcomes published by referral centers. Ad 2). Intraoperative neuromonitoring decreased the incidence of transient RLN paresis in repeat thyroid operations compared with nerve visualization alone. The prevalence of permanent RLN injury tended to be lower in thyroid reoperations with neuromonitoring, but statistical validation of the observed differences requires a sample size of 920 NAR per arm.