During the COVID-19 pandemic, sleep patterns may be altered in the absence of clear routines, due to the threat of latent risk of infection, symptoms of fear and stress that affect sleep quality and favor the development of sleep disorders are strengthened. The aim of this study was to evaluate the mediating role of perceived stress between fear of COVID-19 and insomnia during the COVID-19 pandemic in Peruvian university students of health sciences. Observational, quantitative and predictive study. The research sample consisted of 479 university students of health sciences, of whom 249 (52%) were women aged 18 to 30 years (Median = 23.36). Structural Equation Modeling (SEM) was applied as a statistical technique for mediation analysis. The results show adequate fit indices of the SEM mediational model, where the relationships between the study variables were significant. The indirect route of perceived stress between fear of COVID-19 and insomnia presented greater magnitude (= 0.36), in contrast to the direct relationship of fear of COVID-19 and insomnia (= 0.28), therefore, the mediating effect of stress in the relationship of the variables was demonstrated.