Thirty-six patients with long-standing psychotic illness randomly selected among attenders at two community centers of Bologna were interviewed as were their therapists, in order to determine prevalence and patterns of substance use, reasons for use and effects on illness. Protocols were the same as used in previous research carried out in Boulder, Colorado. For all substances, except stimulants and over-the-counter products, prevalence rates were lower in the Bologna sample than in Boulder. Overall lifetime rates of substance use were significantly lower in the Bologna sample. Nevertheless 47.2% of the Bologna sample had a lifetime moderate to severe drug use and nearly two-thirds of the sample had a current drug use of some severity. Reasons for use equally reflected attempts to alleviate unpleasant emotional states and recreational purposes. Patients with high degrees of psychopathology had significantly lower scores on severity of drug use.