A survey was made of the work and hobbies of 658 patients with the carpal tunnel syndrome. Seventy-nine per cent of the patients were employed in work requiring light, highly repetitive movements of the wrists and fingers. Fifty-one per cent of the unemployed housewives knitted. It is suggested that this type of manual activity can be a causal factor in the development of the, so-called, ‘spontaneous’ carpal tunnel syndrome.