Background. insomnia is described as an insufficient amount or quality of sleep that lasts for at least a month. sleeplessness in the group of professional drivers may lead to accidents and other road incidences. factors influencing the work of drivers include their work time -the amount of time they spend driving their vehicle. Objectives. the aim of the study was to estimate the frequency of the occurrence of insomnia among professional drivers, taking into consideration daytime sleepiness, socio-demographic variables and hourly work organization. Material and methods. study was conducted on 94 professional drivers from the zachodniopomorskie region: 25 (26.60%) paramedics, 24 (25.53%) police officers, 23 (24.47%) fire fighter drivers and 23 (24.47%) truck drivers. a questionnaire was used with the following components: athens insomnia scale (ais), epworth sleepiness scale (ess) and an original questionnaire containing questions regarding socio-demographic data and health behaviors. Results. insomnia was diagnosed in 12 professional drivers (12.77%). among them the majority were truck drivers -4 respondents (4.26%). a relationship between the age of respondents and occurrence of insomnia measured with the ais scale was found. a relationship between insomnia and drivers posing a threat to road traffic was also found (χ 2 = 19.95; p = 0.005). people suffering from moderate daytime sleepiness are 35 years old on average. Conclusions. drivers older than 35 and those with BMi above 28 are groups with the highest risk of suffering from insomnia. drivers with insomnia more frequently pose a threat to road traffic. drinking coffee has no impact on insomnia and daytime sleepiness. Key words: insomnia, drivers, epworth sleepiness scale, athens insomnia scale. Summary ISSN 1734-3402, eISSN 2449-8580this is an open access article distributed under the terms of the creative commons attribution-noncommercial-sharealike 4.0 international (cc By-nc-sa 4.0). license (http://creativecommons.org/licenses/by-nc-sa/4.0/). Wolińska W, tatol p, zdziarski k, karpeta-pawlak ie, Mroczek B. occurrence of insomnia and daytime somnolence among professional drivers.