The procedure for involuntary hospitalizations is prescribed by the ZZODS and is intended for people with severe mental disorders that pose a risk to themselves or other people. According to numerous studies, patients with chronic mental disorders such as schizophrenia and other psychoses have an increased risk of involuntary hospitalization. The aim of this study was to observe the impact of the COVID-19 pandemic on involuntary hospitalizations and thus on mental health of the population. Numerous studies have analyzed the impact of social isolation during the pandemic on mental health, concluding that in addition to negatively affecting the mental health of women, men, children, young people and the chronically ill, it has a particularly strong impact on patients with psychiatric disorders. The research includes 201 patients involuntarily hospitalized at the Psychiatric Clinic of the University Hospital Centre Rijeka in the period from 2018 to 2021. Patients were divided into two larger groups according to the date of hospitalization (before the covid pandemic or during the covid pandemic) and compared based on gender, age, diagnostic categories, number of previous hospitalizations at the Psychiatric Clinic, length of stay, and place of discharge. Also, the difference in the number of patients before and during the covid pandemic was analyzed, as well as the period of lockdown in the Republic of Croatia. The results of the study indicate an increase in diagnoses of mood disorders and delusional disorders, and a decrease in diagnoses of personality disorders during the pandemic. Compared to the period before the pandemic, a smaller number of patients were hospitalized during its duration, the share of female patients increased, as well as the number of discharges home, while the number of discharges in Psychiatric hospital Lopača decreased. The lockdown period is characterized by a decline in the number of involuntary hospitalizations.