The objective of the study was to determine the concentration of BMP-15 and GDF-9 in the fluid of follicular cysts and ovarian follicles, and to compare their concentrations in mono- and polyoocyte follicles in gilts. The study involved two experiments conducted on the ovaries collected post-slaughter from gilts (7-8 months old). The first experiment covered 31 follicular single cyst gilts (15-25 mm in diameter) and 41 gilts without cysts. Follicular fluid from follicles of 8-10 mm in diameter (n=41) and 5-8 mm in diameter (n=41), and cystic fluid (n=31) were collected for analysis. The second experiment involved collecting follicular fluid from poly- (n=19) and monooocyte (n=22) follicles. The concentration of BMP-15 and GDF-9 was then determined in the samples using specimen-specific ELISA kits. The differences in the concentration of these factors were calculated by means of analysis of variance and a posthoc test. Duncan’s multiple range test was used to verify the significance of differences at P<0.05 and P<0.01. In addition, correlations between the factors were calculated. BMP-15 and GDF-9 levels in the cystic fluid were significantly higher than those in the follicular fluid (P<0.01). However, no differences were observed between various size follicles or between mono- and polyoocyte follicles. BMP-15 and GDF-9 concentrations were found to be positively correlated (P<0.01). Differences in BMP-15 and GDF-9 concentrations in ovarian follicles and follicular cysts, as evidenced by our study, indicate that these factors may be related to folliculogenesis disorders in gilts. What is more, the number of oocytes in ovarian follicles does not influence the intrafollicular concentration of BMP-15 and GDF-9.