BACKGROUND The delay on the onset of specific treatment has several prognostic implications for psychotic patients. Duration of untreated psychosis (DUP) has been considered a prognostic variable. A longer DUP has been associated with a poor clinical outcome. OBJECTIVE To determine the DUP in a sample of first-episode psychotic patients and its relationship with recovery and relapse on a one-year follow-up study. METHODS A sample of 66 first-episode psychotic patients was recruited and divided according to their diagnoses in affective and non-affective psychoses. Diagnoses were obtained with SCAN and DUP was registered for each patient. A clinical assessment for psychotic and affective symptoms was performed using standardized instruments. RESULTS All patient studied showed clinical improvement during follow-up. Patients with a longer DUP showed poorer psychosocial adjustment and lower recovery indexes. Treatment suspension was the main variable associated with relapse. CONCLUSIONS DUP is an important prognostic variable. Early detection programs are required to decrease the period between illness onset, diagnosis and treatment in first-episode psychotic patients.