In the words of M. Candau, accidents rate as “the world's third worst killer”, and in the industrialized society, with increasing hazards to life and health, it is of the utmost importance to find ways to reduce their number as well as their deadly and crippling effects. Accident research will undoubtedly reap great benefits from the epidemiological approach, formerly regarded as primarily a means for the study of infectious diseases. The author is at present specializing in the study of fall accidents, using epidemiological methods. Here he gives an account of his epidemiological accident study of falls on stairs, which constitutes the socio-medical part of a broad investigation project, a survey made by sections at the Lund and Stockholm Institutes of Technology in collaboration with medical institutions at Lund University. The results reveal facts of great interest concerning prevention, and it is to be hoped that accident researchers in general will pay more attention to the value of epidemiological methods, in order to obtain a flexible foundation for our increasing knowledge of feasible preventive measures.