Pemetrexed (Alimta ) is a novel multitargeted antifolate that inhibits 3 enzymes involved in folate metabolism and purine and pyrimidine synthesis. These enzymes are thymidylate synthase, dihydrofolate reductase, and glycinamide ribonucleotide formyltransferase. This agent has broad antitumor activity in phase II trials in a wide variety of solid tumors. In non-small-cell lung cancer (NSCLC), single-agent activity has been documented in the first- and second-line settings. Promising activity has also been demonstrated when pemetrexed is combined with cisplatin and gemcitabine. A pivotal phase III study in mesothelioma has been presented, indicating the superiority of pemetrexed in combination with cisplatin versus cisplatin alone in this disease. Approval for pemetrexed in combination with cisplatin in advanced mesothelioma is expected within the next 12 months. This review discusses the activity of pemetrexed in NSCLC.