The addition of aprepitant to 5HT-3 antagonist and steroid is approved for the prevention of acute and delayed nausea for highly emetogenic chemotherapy (HEC). The use of oral aprepitant 3 day regimen has been evaluated in moderately emetogenic chemotherapy. However, its use has not been explored in carboplatin containing combination regimens in advanced non-small cell lung cancer (NSCLC). An equivalency study compared fosaprepitant, a 1-day intravenous formulation of aprepitant, with oral aprepitant. Findings demonstrate equivalence between the agents for complete response and both emesis and nausea control. Fosaprepitant was endorsed by the ASCO Update Committee as an acceptable NK1 receptor antagonist. However, there has been no evaluation of this iv formulation with moderately emetogenic chemotherapy and specifically carboplatin containing regimens in NSCLC. Therefore, the investigators propose a double-blind, randomized placebo controlled cross-over phase II study assessing the role of fosaprepitant in the prevention of nausea and emesis in patients receiving carboplatin based chemotherapy for advanced NSCLC.