Sickness absenteeism has been considered a complex phenomenon, with multiple etiologies, including factors related to both the environment and the organization of work, as well as individual factors. However, it has been studied in restricted occupational groups. To analyze the profile of sickness absenteeism among workers of a health company in Cuiabá, state of Mato Grosso, Brazil, in 2015 and 2016. Cross-sectional study, with workers present in the company's payroll from 01/01/2015 to 12/31/2016, with a medical certificate approved by the occupational physician to justify absence from work. The variables analyzed were the chapter of the disease according to the International Statistical Classification of Diseases and Health Problems, sex, age, age group, number of medical certificates, days of absenteeism, the section of work activities, function performed at the time of sick leave, and indicators related to absenteeism. 3,813 sickness leave certificates were registered, which corresponded to 45.4% of the company's workers. The mean number of sickness leave certificates was 4.0, which led to 18.9 days of absenteeism on average. The highest percentages of sickness absenteeism were found in women, in those with diseases of the musculoskeletal system and connective tissue, in those working in Emergency Room sections and in the roles of customer service agents and analysts. Considering the longest periods of absence, the most identified categories were older people, circulatory system diseases, work in the administration section, and the motorcycle courier position. A considerable percentage of sickness absenteeism was identified in the company, requiring managers to invest in strategies to adapt the work environment.