The effect of smoking on hearing was investigated among 199 professional forest workers and 171 shipyard workers. The effect of age on hearing was corrected with Robinson's model for an audiologically screened population. The exposure of the subjects to noise and their history of tobacco smoking were examined, with special reference to blood pressure and occupational Raynaud's phenomenon. Smoking without the presence of any other risk factors did not increase the risk for sensory neural hearing loss, but smoking in combination with elevated blood pressure and occupational Raynaud's phenomenon put workers at higher risk for hearing loss than any of these factors alone.