Early initiation of oseltamivir within 48 h to 5 days from illness onset has been associated with improved survival among patients with community-acquired influenza pneumonia. Delay of hospitalization limits early treatment and the survival of patients. To date, the effects of early oseltamivir initiation within 24 hours from admission on patient mortality has remained unknown. This retrospective study reviewed and analyzed the clinical and non-clinical outcomes of 143 patients, with community-acquired influenza pneumonia, who received oseltamivir within 24 h (group A) and after 24 h (group B) from admission. Among the patients, 82 (57.3%) received oseltamivir within 24 h while 61 (42.7%) received oseltamivir after 24 h. The median time from symptom onset to admission for group A and group B was not statistically significant (P < 0.001). The 14-day mortality rate was 9% and 23% for group A and B, respectively (P = 0.03), while the 30-day mortality were 15% and 30% for group A and B, respectively (P = 0.05). Administration of oseltamivir within 24 h significantly affected 30-day mortality rates (adjust OR: 0.14, 95% CI: 0.47-0.04, P < 0.01), particularly among patients with respiratory failure at admission (adjust OR: 0.08, 95% CI: 0+.30-0.06, P < 0.01). Survival analysis of patient with influenza pneumonia and respiratory failure at admission demonstrated significant difference between those who received oseltamivir within and after 24 h (P = 0.002). The results indicated that early oseltamivir initiation within 24 h improved the survival outcome mainly among those with respiratory failure at admission.