A hundred schizophrenic patients admitted to the "10 de Octubre" Clinical-Surgical Teaching Hospital and 158 schizophrenic patients admitted to the Psychiatric Hospital, both in Havana, and 100 control healthy individuals who did not consume psychopharmacons were studied. They underwent intradermal tests with toxoplasmin. Differences in reactor percentages between patients and healthy individuals were statistically significative as it has been reported in the foreign medical literature. The highest percentage of reactors in the group admitted to the Psychiatric Hospital where most advanced schizophreniacs are found leads to the conclusion that the more severe the patient state the higher the frequency and intensity of test reactivity among patients. Other factors as the dwelling conditions, age and sex are analyzed.