BackgroundPrenatal care in adolescents is one of the most important challenges worldwide, especially in the regions with a specific culture and traditions. The purpose of this study was to investigate the effectiveness of group counseling on knowledge and performance of pregnant adolescents in prenatal care in a Kurdish region in Iran.MethodsThis quasi-experimental study was conducted on pregnant adolescents attending in the health centers of Mahabad, a Kurdish city in Iran. Using a multi-stage cluster sampling method, after random selection of four health centers as the intervention and the control, primigravida adolescents with gestational age of 16–20 weeks filled out the demographic and midwifery characteristics questionnaire, as well as a prenatal care knowledge and performance of pregnant adolescents’ questionnaire. Then 102 pregnant adolescents (51 people in the control centers and 51 people in the intervention centers), who responded correctly to <50% of the questionnaire items were included in the study. Six sessions of group counseling about prenatal care were held for the intervention group. The control group received the routine prenatal care. Knowledge and performance of pregnant adolescents about prenatal care were compared inter and intra two groups 1 month after the end of the sessions through descriptive-analytic tests including chi-square, independent T and paired T tests.ResultsIn contrast to the control group, the mean scores of adolescents’ knowledge about prenatal care increased after the intervention (from 17.51 ± 5.93 to 24.67 ± 5.79) and showed significant difference to the control group (p < 0.05). In addition, the mean scores of adolescent care performance in the intervention group increased (from 5.80 ± 2.19 to 10.33 ± 2.55) and showed significant difference to the control group (p < 0.05).ConclusionThe results of the present study show the positive effects of prenatal care counseling on increasing knowledge and improving the performance of pregnant adolescents.