The aim of the presented study was the assessment of zinc and copper concentrations among patients with MDD and healthy volunteers and additionally comparison of those concentrations between patients with MDD and BD. 110 patients with the diagnose of BD and 114 with MDD were qualified to this case-control study. To assess the levels of microelements the flame atomic absorption spectrometry in zinc samples was used and the electrothermal atomic absorption spectrometry for copper samples was used.The zinc level in MDD patients in depression was significantly lower than in healthy volunteers. Between MDD patients in remission and healthy volunteers no differences were obtained. Copper levels analysis have not shown significant differences between MDD patients (in remission or depression) and healthy volunteers nor among majority of analyzed correlations. The levels of copper and zinc in BD and MDD patients (both in remission and depression) did not differ. The zinc concentration has some features of state marker with no features of trait marker of MDD. Copper level does not have any features of a state or trait marker of MDD. The lack of differences in zinc and copper concentrations between patients with bipolar disorder and major depressive disorder might indicate that those disorders have similar etiology.