Research needs in identifying preventive measures dealing with working time arrangements and associated sleep problems are reviewed. These needs are based on the recognition of a range of risk factors for health involving disturbed circadian rhythms leading to various levels of sleep deficits. The review takes account of recent joint change approaches that address both working time arrangements and various relevant intervening factors. As examples of such approaches, voluntary industry-based guidelines for improving shift work are examined. Also reviewed is evidence indicating the effects of improved working time arrangements and sleep hygiene on the tolerance of workers working irregular shifts. Trends in action-oriented risk assessment are further discussed as the effects on health and sleep of these workers may be modified by complex aspects related to working situations, family and social conditions, personal characteristics and social support. Generally relevant are not only the relationships between sleep-affecting factors and health, but also advances in taking the various support measures. The effective use of participatory steps is found important in dealing with working time arrangements and associated health and sleep problems together. It is thus considered important to study (a) the efficacy of joint change approaches addressing complex sleep and health factors, (b) effective procedures for action-oriented health risk assessment in various work life situations, and (c) the relevance of innovative participatory steps to improving health and tolerance of workers. Future research topics mentioned by the participants of the international symposium on night and shift work held in Santos in 2003 are presented, and international efforts to promote research into these aspects in field conditions are discussed. Interactive research involving local people appears crucial.