The aim of the study was to evaluate the levels of adipokines such as adiponectin, resistin, leptin as well as C-peptide in overweight and obese pregnant women. The adipokines and C-peptide concentrations were measured in the group of 38 overweight/obese pregnant women (BMI > 25 kg/m2) and in 42 pregnant women of normal weight (BMI < 25 kg/m2) with ELISA tests between 24th and 34th weeks of gestation. The overweight/obese women compared to lean ones were characterized by significantly higher concentrations of leptin (43.44 ± 31.41 vs. 21.29 ± 12.67 ng/mL, p = 0.0001) and C-peptide (2.77 ± 1.88 vs. 2.25 ± 1.42 ng/mL, p = 0.034). There were no significant differences between groups in resistin (17.39 ± 7.59 vs. 15.76 ± 6.64 ng/mL, NS) and adiponectin (6.93 ± 3.52 vs. 8.07 ± 6.53 μg/mL, NS) levels. In the overweight/obese patients, no relationships between the adipokines, C-peptide and CRP concentrations were found. BMI was negatively correlated with the resistin levels (R = -0.406, p = 0.011). The significant correlation between leptin and C-peptide concentrations was observed in the study group (R = 0.517, p = 0.012). In the control group, the negative correlation between adiponectin concentrations and BMI was shown (R = -0.446, p = 0.003). The higher levels of leptin in the overweight and obese pregnant women seem to reflect the leptin resistance condition and the higher levels of C-peptide in this group is suggestive for hyperinsulinemia. The positive correlation between C-peptide and leptin levels but not with resistin and adiponectin might confirm the role of leptin in the hyperinsulinemia development in overweight and obesity during pregnancy.