Shift work and night work in particular, account for numerous disturbances in circadian biological rhythms of physiological activities. Shift workers most frequently complain of sleep disturbances manifested among others by sleep duration and quality, as well as by time of proper sleep and naps. Among methods used for the sleep assessment, subjective tests: sleep value questionnaires and 24-h EEG, are most common, however actigraphy is recently considered to be more useful. This paper presents the results of the authors' investigations on the circadian rhythms: locomotor activity and sleep in air traffic controllers (ATCs) at the Okecie Airport of Warsaw. Sleep disturbances, most often sleep latency, shortening of the main sleep and more frequent naps increase with age and work experience. The knowledge of sleep disturbances may, in individual cases, be helpful in choosing the best possible strategy to cope with sleep deficit in shift workers.