On the basis of symptomatology, 51% of 146 fellers from seven coastal lumber camps in British Columbia were found to be suffering from vibration while finger disease (VWFD). Symptoms were present in 70% of the men who had been engaged in felling for 11 to 15 years and in 75% of the men who had been employed in this occupation for more than 20 years. Prevalence rotes were not changed by the exclusion of 57 fellers with a history of vibration exposure other than the chain saw, or with a history of other possible secondary causes. The prevalence of symptoms in an age-corrected control group was 2%. There was objective evidence of disease (delayed finger rewarming after cooling) in 31 of the 43 fellers with symptoms (72%) and in 13 of the 74 controls (18%) without symptoms. The median latency period for fellers with symptomatic VWFD was 7.3 years. There was no evidence that the condition was related to cigarette smoking.