Lung cancer is the leading cause of cancer death worldwide. Despite the introduction of new agents and schedules, chemotherapy still obtains unsatisfactory overall response rates, rare complete remissions and responses of relatively short duration. The inhibitor of apoptosis proteins (IAPS) are a family of caspase inhibitors that selectively bind and inhibit caspases-3, -7, and -9. As caspase activation is central to apoptosis, novel therapeutic drugs that target IAPs enabling apoptosis to occur have potential as a treatment of malignancy. Several agents that target core components of the apoptotic signalling pathway are currently at an early stage of development. This review reports the progress being made in characterising the IAP family, with a focus on the available data relevant to the treatment of lung cancer.