In this study, we investigated the frequency of Raynaud's phenomenon (RP) in medical students and hospital personnel and determined associated factors. Students and hospital personnel of our medical faculty (1,414 subjects; 838 females, 576 males, mean age, 27.2+/-6.6) were questioned for symptoms associated with RP, and the presence of smoking and headache. 530 subjects (37.5%) defined color changes on cold exposure. 51 subjects (3.6%) had biphasic or triphasic color changes (definite RP). The prevalence of definite RP in females (4.8%) was significantly higher than in males (1.9%) (P=0.005). The frequency of smoking subjects (45.1 vs. 28.8%) was significantly higher in patients with RP (P=0.009). There was numbness and/or paresthesia in 174 subjects (12.3%) who defined uniphasic color change on cold exposure (possible RP). Female sex and being a smoker were factors associated with RP in our study.