Introduction: The goal of our study was to investigate and evaluate the contraceptive behavior in teenagers from our family planning centre that services two different religious and socioeconomic populations living in the Thrace area. Methods: During the last 10 years 115 Christian Orthodox (group A) and 53 Muslim teenagers (group B) were enrolled in our retrospective study. Contraceptive practice attitudes were assessed by a questionnaire. Religion, demographics, socio-economic characteristics were key factors used to discuss contraception and avoid unplanned pregnancy in each group and to compare with the contraceptive method used. Results: The most used contraceptive method—about two times more frequently—among Christian Orthodox participants was the oral contraceptive pill (p = 0.015; OR = 1.81, 95% CI = 1.13–2.90), while in the other group the use of condoms and IUDs was seven and three times more frequent, respectively. Our family planning centre was the main source of information for contraception. Conclusions: During adolescence, the existence of a family planning centre and participation in family planning programs plays a crucial role to help the teenagers to improve their knowledge and choose an effective contraception method.