The purpose of this study was to investigate the prevalence of dietary supplement consumption and other effective factors in athletes in Tabriz. 150 male athletes (23±5 years) from different sport fields volunteered to participate in this study. A 17-item questionnaire was used to investigate subjects’ sport field and sport history, reasons to consume dietary supplements, sources of information on these supplements and the centers in which they can be provided. At the time of study, 45% (N = 68) of participants consumed at least one supplement and 21% (N=31) used dietary supplements in the past. The most popular supplements were creatine (43.3%), whey protein (17%) and multivitamin (13%). The results showed that the main reason for consuming dietary supplements was to meet the dietary needs (35%). Supplement consumption was significantly different in different sport fields. 34% of participants listed coaches as their best source of information on dietary supplements. The majority (44%) of subjects purchased their supplements from pharmacy. The results of this study agreed with previously published data on prevalence of dietary supplement consumption.