Background The relationship between work and health is complex and bidirectional. It has individual and collective aspects resulting from working conditions and interpersonal relationships. Absenteeism, a complex phenomenon, represents for some workers the expression of health and work relationship. It is considered as an indicator of a person’s physical and mental health status. Aims: To identify determinants of sickness absence among nurses in a Tunisian university hospital.

Methods A cross-sectional study carried out in a Tunisian University Hospital. We included medical absences declared to the employer by nurses during one year. The study was conducted in two successive phases: data collection of absence from the hospital direction (human resources), then a standardized self-administered questionnaire was distributed to the target population. This questionnaire included a socio-professional survey and a questionnaire on Psychological and Organizational Constraints (POC), using a version applicable to nurses (IDE).

Results The global absence rate was 6.58. Absenteeism was statistically associated with age (p = 0.035), marital status (p = 0.005) and the presence of medical and surgical history (p < 10¯³). The number of absence days was statistically higher among nurses with a pathological professional history (p = 0.019) and among those with an occupational tenure higher than 15 years (p = 0.034). For the psycho-organizational constraints studied, the period of absence was statistically associated with the organization that did not allow communication (p = 0.001), the lack of support from the health manager (p = 0.001) and a shortage of staff (p < 10¯³). The multivariate regression analysis showed as determinants of absenteeism: medical history (p < 10¯³; 95% CI = [2.21; 8.18]), surgical history (p = 0.001; 95% CI = [1.71; 9.12]) and the lack of support from the health manager (p = 0.001; 95% CI = [1.58; 6.34]).

Conclusion This study allowed us to identify some determinants of absenteeism among nurses.