Lung cancer is the leading cause of cancer-related death worldwide and has frequently been associated with over-activated protein kinase B (PKB)/Akt. Akt is a serine/threonine protein kinase that plays an important role in cell growth, proliferation, and survival. Many lines of evidence point to the contribution of deregulated Akt in development or progression of lung cancer. In addition, recent studies have demonstrated that cancer cells defend themselves from therapeutic treatment through activation of pro-survival signals, including the Akt pathway. In this review, we described the way in which the Akt pathway is activated in development and progression of lung cancer, and the way in which deregulated Akt plays a significant role in lung tumorigenesis and resistance to chemo- or radiotherapy. In this review, we also discussed the potential of the Akt pathway as a target of lung cancer therapy.