The purpose of this multi-center Phase II trial is to examine the impact of pemetrexed/carboplatin in the preoperative treatment of patients with select stage IB, II,and III non-squamous NSCLC. Because patients with non-squamous type NSCLC have been shown to have better survival rates than patients with squamous tumors when given pemetrexed with a platinum agent, only patients with non-squamous NSCLC (adenocarcinoma, large cell, and undifferentiated), not including squamous histology, will be allowed to participate in this study. If this novel regimen proves to be safe and active in this setting, it will provide rationale for further investigation in a larger, prospective, randomized trial.