OBJECTIVE Effective early and persistent antipsychotic treatment in recently diagnosed schizophrenia may positively impact long-term outcomes. Paliperidone extended-release (ER) was assessed in this population. METHODS Post hoc analysis of pooled data from three 6-week, double-blind (DB), placebo-controlled, and three 1-year open-label (OL) studies of paliperidone ER in schizophrenia patients. Data stratified by time since diagnosis (< or =3 vs. >3 years). RESULTS At DB (n = 1193) and OL baselines (n = 744), 259 (21.9%) and 188 (25.3%) patients were diagnosed < or =3 years. At DB end point, both populations improved with paliperidone ER versus placebo on Positive and Negative Syndrome Scale (PANSS) total, Clinical Global Impressions-Severity and Personal and Social Performance (PSP) scale scores (all P < 0.05). At OL end point, there were significant improvements from DB baseline in both populations on these scales (P < 0.0001), with greater improvement in the < or =3-year population on PANSS total (P < 0.001) and PSP (P < 0.001) scores. During DB treatment, only the < or =3-year population reported adverse events (AEs) in > or =5% (placebo-adjusted rate) of subjects receiving paliperidone ER: akathisia, extrapyramidal disorder not otherwise specified and somnolence. During OL treatment, akathisia and somnolence occurred more frequently (> or =5%) in the < or =3- versus >3-year population. OL study completion rates were 51.1% in < or =3-year, and 48.2% in >3-year subjects. CONCLUSIONS Paliperidone ER significantly improved symptoms and functioning in schizophrenia patients, regardless of time since diagnosis. Recently diagnosed patients who continued treatment exhibited greater symptom reduction and functional benefit over the long term. Results also suggest that these patients may be more susceptible to certain AEs.