Objective-Raynaud's phenomenon (RP) is comprised of repeated episodes of colour changes of the skin of digits on cold exposure or emotional stress. The prevalence of RP in the general population is variable fluctuating between 4%-15%, among surveys. The aim of this study was to estimate the prevalence of RP in a healthy working Greek population and to investigate the possible association of RP with various demographic, social and other factors. Methods-A total of 756 employees of the University Hospital of Ioannina was included in the study. They belong to the administrative (120 subjects), nursing and technical (a representative sample of 418 and 218 subjects, respectively) personnel. Five hundred subjects (111 men and 389 women) responded in a face to face interview based on a specially conformed questionnaire. The study began in November 1997 and was completed in March 1998. Results-Twenty six subjects with RP (1 man and 25 women) were found. Their mean (SD) age was 32.73 (5.77) years. The prevalence of RP was 5.2% (0.9% in men and 6.4% in women). The sex ratio, male/female, was 1/7.1. An association between RP and migraine was found. However, there were no significant correlations of RP with smoking, alcohol and coVee consumption, dietary habits, occupational history and drug exposure. No social or other demographic parameters associated to RP frequency were found. Conclusions-The prevalence of RP (5.2%) in the population studied is relatively low compared with previous studies. RP focuses on the fourth decade of life and aVects mainly women. There was no evidence of any correlation of RP with social, environmental or personal parameters while an association of RP with migraine was found. Geographical or genetic factors, or both, may be responsible for these results.