Abstract Background Social dysfunction is an important outcome for schizophrenia and can be measured by the evaluation of social skills. Objectives To compare social skills in patients with schizophrenia classified according the degree of treatment response and severity of psychopathology with normative controls by using the Del Prette Social Skills Inventory (SSI). Methods Cross-sectional study where the 38 questions SSI was applied to 62 outpatients with schizophrenia and compared with data of 99 normal controls from the general population. The SSI was evaluated by five domains. Psychopathology was measured by the Positive and Negative Syndrome Scale (PANSS). Patients were classified as Treatment Resistant (TRS) and Non Treatment Resistant (NTRS) by the International Psychopharmacology Algorithm Project (IPAP) criteria. ANCOVA was used to control for demographic differences between populations. Results Patients showed significantly more impaired than controls except for aggressiveness control. When variables such as age, age of onset, schooling or medication dose entered as covariates, differences between controls and patients, or TRS with NTRS, almost disappeared. The SSI and PANSS showed an inverse relationship between their domains. Discussion The SSI may represent a useful tool for evaluation of social skills in schizophrenia. Antipsychotics may exert a protective effect on social skills.