Purpose The paper aims to analyse the impact of mental health problems on the academic performance of university students using data from a cross-sectional survey of Ukrainian university students during the war. The prevalence of mental health problems among students with their subsequent division into different severity groups is investigated.Methods The study combines a cross-sectional survey method to collect data and a regression analysis technique to identify mental health problems that have the most negative impact on students' academic performance during the war. The survey questionnaire includes a demographic section, mental health screening tools, as well as Work Productivity and Activity Impairment: Special Health Problems (WPAI: SHP) section, adapted for the purpose of the study. The data sample includes responses from 1398 university students from different regions of Ukraine.Results According to survey data 85.8% of all respondents had depression symptoms, 66.1% – anxiety symptoms, 56.9% – symptoms of sleep disorder, and 48.1% – PTSD symptoms. Results of econometric modeling confirms the devastating effect of mental health problems on academic performance of university students during the war, in particular, a severe depression symptoms, anxiety disorder symptoms and sleep disorder symptoms are associated with 17.4%, 12.2% and 11.0% decrease in academic performance of university students, respectively.Conclusion The prevalence of mental health problems and related academic performance impairment among students during wartime become a challenge for the successful recovery of Ukrainian society and therefore require a quick response at both the institutional and public policy levels.