The aim of this study was to examine athletes’ and coaches’ attitudes and intentions with regard to doping, using the theory of planned behavior (TPB) model. This model , explains all the behaviors which are related to self-control, based to the theory that intentions are influenced by attitude, perceived behavioral control and subjective norms. The variable “morality” was added to the original model. One hundred and forty-three athletes (mean age = 20.93 ± 2.90) who were involved in competitive sports and 50 coaches (mean age = 35.74 ± 7.80) participated in the study. A questionnaire was administered to assess the demographics (age, gender, sport type, competitive level, years of sport participation and education), attitudes, subjective norms, perceived behavioral control, intentions, morality and doping choices of athletes and coaches with regard to doping. The results showed that attitudes (62%), perceived behavioral control (3%), and morality (4%) were significant predictors of athletes’ intentions to engage in doping choices but that coaches’ only attitudes were the most important predictor of intentions to engage in doping choices (72%). The most important predictors of 1st and 2nd doping choices were intentions (78% and 68%) and perceived behavioral control (1%) for athletes and intentions (84% and 79%) for coaches.