This study is conducted on Iranian pharmacists, coaches, and athletes regarding sports supplements to assess their knowledge, attitude, and practice (KAP) regarding sports supplements. Methods: This was a cross-sectional study conducted in 2015. The study population consisted of all community pharmacists, bodybuilders, and bodybuilding coaches. The questionnaire was applied consisting some demographic questions and 25 questions for assessing KAP (6, 9, and 10, respectively). The collected data were analyzed with independent t-test, ANOVA, and Pearson correlation. Findings: In all three studied groups, the mean of KAP was upper than intermediate level 3 (P < 0.05) except the pharmacists' knowledge. A statistically significant difference appears between knowledge and age of pharmacists (P = 0.007). In addition, there was a significant relationship between coaches' practice and age (P = 0.04). Conclusion: According to the results although the studied groups have the intermediate level of KAP, organized and regular education courses are highly recommended along with paying more attention to the curriculum taught in the pharmacy schools according to the community current needs.