Comparison of general blood test parameters, biochemical and hormonal profiles, and blood coagulation system parameters did not reveal differences between the groups, with the exception of a higher level of prolactin in patients with endometriosis compared to the comparison group (468.21 ± 303.23 mlU/L vs. 276.52 ± 125.91 mlU/L, p = 0.041) and lower values of platelets (276.89 ± 64.14 109 per L vs. 313.82 ± 85.14 109 per L, p = 0.042) and thrombocrit (0.27 ± 0.05 L/L vs. 0.31 ± 0.07 L/L, p = 0.016) in patients with endometriosis. Here, PRL is linked to endometriosis.