Objectives: To evaluate the efficacy and safety, we conducted a randomized phase II study of pemetrexed (Pem) versus Pem + bevacizumab (Bev) for elderly patients with non-squamous non-small cell lung cancer (NSqNSCLC). Patients and methods: The eligibility criteria were as follows: NSqNSCLC, no prior therapy, stage IIIB/IV disease or postoperative recurrence, age: ≥75 years, performance status (PS): 0-1, and adequate bone marrow function. The patients were randomly assigned (1:1 ratio) to receive Pem or Pem+Bev. The primary endpoint was progression-free survival (PFS). The secondary endpoints were the response rate, OS, toxicities, and cost-effectiveness. Results: Forty-one patients were enrolled and 40 (20 from each group) were assessable. Their characteristics were as follows: male/female=23/17; median age (range)=78 (75-83); stage IIIB/IV/postoperative recurrence=1/30/9; PS 0/1=11/29. All cases involved adenocarcinoma. There was no significant intergroup difference in PFS and the median PFS (95% confidence interval) values of the Pem and Pem+Bev groups were 5.4 (3.0-7.4) and 5.5 (3.6-9.9) months, respectively (p=0.66). The response rate was significantly higher in the Pem+Bev group (15% vs. 55%, p=0.0146), and there was no significant difference in OS (median: 16.0 vs. 16.4 months, p=0.58). Grade 3 and 4 leukopenia, neutropenia, and thrombocytopenia were seen in 10 and 30, 20 and 55, and 5 and 5 cases, respectively. Drug costs were higher in the Pem+Bev group (median: 1,522,008 vs. 3,368,428 JPY, p=0.01). No treatment-related deaths occurred. Conclusions: Adding Bev to Pem did not result in improved survival in the elderly NSqNSCLC patients. Compared with Pem+Bev, Pem monotherapy had similar effects on survival, a more favorable toxicity profile, and was more cost-effective in 4 elderly NSqNSCLC patients. Pem monotherapy might be one of the optional regimen for NSqNSCLC patients aged ≥75 years.