HIV testing is not yet a routine procedure in most mental health settings although adults with severe mental illness (SMI) are disproportionately affected by HIV/AIDS.

We focused our attention to explore if the appropriate care of patients with SMI may include a routine HIV testing offering and thus contribute to diagnose HIV-infected persons earlier in the course of their infection.

We present three case histories related to primary HIV diagnosis in patients presenting with different psychiatric disorders, admitted to Modena teaching Hospital in the passed two years.

Psychiatric symptoms delayed HIV diagnosis in all of the three reported cases.

The case histories here presented suggest that HIV testing is appropriate in the care of people with SMI, avoiding delay in HIV diagnosis with an obvious clinical benefit for the patient. Further studies are needed to assess the prevalence of HIV in those patients. These will be able to validate psychiatric diseases within a specific HIV indicator diseases list and help identifying a segment of the population in which HIV test must be routinely offered as a public health strategy, to face the burden of undiagnosed HIV infection.