We aimed to determine the prevalence of hepatitis B surface antigen (HBsAg) among chronic schizophrenia patients in Jordan. Over a period of 12 months, 192 patients (106 male and 86 female) were tested for hepatitis B virus (HBV) by enzyme immunoassay. An equal number of age- and sex-matched healthy controls was also tested. Of the schizophrenia patients, 14 (10 male and 4 female) were positive for HBsAg while only 5 (4 male and 1 female) of the control subjects tested positive. The difference was not statistically significant but it indicates that chronic schizophrenia patients are a risk group for HBV infection and likely to benefit from preventive measures (health education and immunization against HBV).