Early and maintained treatment is important for better long-term outcomes in schizophrenia. We hypothesized that treatment with injectable risperidone long-acting therapy (RLAT) would be associated with improved outcomes in recently diagnosed patients compared with those having longer illness duration. Post-hoc analyses were conducted from a 1-year study of stable patients receiving RLAT (25 or 50 mg every 2 weeks) to compare patients diagnosed with schizophrenia in ≤3 years (recently diagnosed; n=57) with those diagnosed more than 3 years (n=266). Relapse rates were 10.5 and 21.8%, respectively [P=0.053, χ2; hazard ratio 2.2 (95% confidence interval=0.95, 5.13)]. Both groups improved significantly in mean total Positive and Negative Syndrome Scale and Clinical Global Impressions-Severity (CGI-S) scores (P<0.01). Recently diagnosed patients showed greater improvement versus patients diagnosed for more than 3 years in adjusted mean Positive and Negative Syndrome Scale total (−10.2±2.0 vs. −3.8±0.9; P=0.004) and Clinical Global Impressions-Severity (−0.5±0.1 vs. −0.2±0.1; P=0.002) scores. The most common adverse events were insomnia (31.6 vs. 26.7%), psychiatric disorders (19.3 vs. 20.7%), headache (15.8 vs. 19.2%), anxiety (12.3 vs. 17.3%), and influenza (10.5 vs. 5.3%). These findings confirm the benefit of RLAT in patients with schizophrenia and suggest that earlier treatment with long-acting preparations is associated with better outcomes.