Objective: To determine clinical efficacy, safety and prognostic factors of pemetrexed plus platinum as first-line treatment in patients with advanced non-small cell lung cancer (NSCLC). Materials and Methods: Clinical characteristics, short-term efficacy, survival and adverse reactions of 47 advanced non-squamous NSCLC patients who had received pemetrexed plus platinum as first-line treatment in Shanghai Pulmonary Hospital from January 2009 to June 2011 were retrospectively analyzed. The Chi-squared test was applied to statistically analyze the overall response rate (ORR), disease control rate (DCR) and toxicity reactions in both groups, while survival data wereanalyzed by Kaplan-Meier and logrank methods, and the COX proportional hazards model was adopted for a series of multi-factor analyses. Results: Only two patients were lost to follow-up. The ORR, DCR, medium progression-free survival time (PFS) and medium overall survival (OS) were 31.9%, 74.5%, 5 months and 15.2 months, while 1- and 2-year survival rates were 63.8% (30/47) and 19.2% (9/47), respectively. Single-factor analysis showed that tumor pathological patterns and efficacy were in association with medium PFS (P<0.05), whereas tumor pathological patterns, smoking history and efficacy were closely connected with medium OS (P<0.05). Multi-factor analyses demonstrated that pathological patterns and efficacy were independent factors influencing OS (P<0.05). The rate of toxicity reactions in degree III/IV was low, including hematologic toxicity marked by decline in white blood cell count and decrease in the platelet count (PLT), and non-hematologic toxicity manifested by gastrointestinal reactions, such as nausea and vomiting. Conclusions: Pemetrexed plus platinum as first-line treatment has excellent efficacy and slight adverse reactions with favorable drug-tolerance in patients with advanced non-squamous NSCLC.