Sleep disorders and related diseases are becoming increasingly relevant for the health and wellbeing of the general and working populations. Sleep disorders affect all aspects of health, showing a bi-directionality with health conditions and comorbidity with several diseases. Consequently, sleep disorders may have severe negative consequences both for the individual and the enterprise, as well as for society on the whole, in terms of health, productivity and social costs. When considering the disturbances of the sleep/wake cycle, it is important to distinguish between those connected with endogenous biological factors from those related to socio-environmental conditions, including work, and those associated with mental and physical diseases, that are often associated and interact with each other. Many sleep disorders are still underestimated and under-valued in clinical practice and, to a much greater extent, in workers' health surveillance. The present paper is aimed at drawing the attention of the occupational health physician to some key issues, particularly regarding excessive daytime sleepiness, obstructive sleep apnea syndrome and shift and night work, as well as their implications in terms of health and occupational consequences. Information on the main aspects of clinical diagnosis and health surveillance, as well as risk management and prevention at the workplace, are provided.