Introduction The study describes and analyzes the hospitalisations due to mental disorders during 2005–2010 in public psychiatric hospital in Belo Horizonte, Brazil.

Methods We conducted a retrospective study of hospitalisation data using the EPI-INFO. Length of hospital stay, main psychiatric diagnoses (ICD-10, WHO) and sociodemographic characteristics were analysed.

Results The predominant hospitalisations group were from men with 20 to 50 years old and patients with mental disorders related to substance use. There were a decreased of total hospitalisations, length of hospital stay and percentual of patients with ICD-10 diagnoses F20-F29. There were increased in the percentual of patients with ICD-10 diagnoses F10-19. Remained constant the percentual of admissions to patients from different places of country.

Conclusion There was a significant decrease in the hospital stay, indicating better quality of hospital care, availability of resources therapeutic, increased care network to outpatients and access to psychopharmacological treatment. But there are a important increased admissions of patients with mental disorders related to substance use. The Psychiatric hospitalisation is important to psychiatric care network and there are changes the profile of diagnoses that need to be evaluated in the planning of public services mental health.