Summary Background In response to the current coronavirus disease 2019 (COVID-19) pandemic the Austrian government issued a lockdown from 16 March to 15 May 2020. As periods of economic and emotional burden have proven to detrimentally affect people’s psychological health, healthcare officials warned that the strict measures could have a serious impact on psychological health, leading to an increase in suicide attempts. Thus, the objective was to provide evidence for this assumption. Methods All adult patients admitted to the trauma resuscitation room of the Medical University of Vienna during the lockdown period following a suicide attempt were included in this analysis, forming the study group. Suicidal patients treated during the same period in 2015, 2016, 2018, and 2019 were pooled to create the control group. The year 2017 was excluded because another major hospital in Vienna was partially closed due to a change in infrastructure, resulting in an increased number of severely injured patients treated at our department. As the lockdown caused a markedly decreased number of patients admitted due to other reasons than suicide the actual number was replaced with the average number of patients admitted in the relevant previous 4 years. Results By comparing the study and the control group based on this realistic estimate we revealed an increase in attempted suicides during the lockdown period (p = 0.001). Demographic, mental health-related, and injury specific patient data did not differ between the groups. Conclusion The results strongly urge for an improvement in crisis intervention and suicide prevention measures in the event of a future lockdown.