A QUESTIONNAIRE survey of university students was undertaken in 1989 to investigate the determi nants of cycling and cycle helmet use. Women were less likely to cycle than men. The main reasons people gave for cycling were economy and con venience. The main reasons people gave for not cyc ling were danger and the risk of bike theft. Different attitudes to the appearance, practicality, and com fort of cycle helmets distinguished to some extent between cyclists who said they would use one regu larly if given a voucher to buy one, and those who would not. This paper suggests ways in which the public health benefits of cycling could be promoted on the basis of findings reported here.