The exocyst complex is a large conserved hetero‐oligomeric complex that consists of Sec3, Sec5, Sec6, Sec8, Sec10, Sec15, Exo70, and Exo84 subunits. It has been implicated in the targeting of vesicles for regulated exocytosis in various cell types, and is also important for targeted exocytosis of post‐Golgi transport vesicles to the plasma membrane. The exocyst complex is essential for membrane growth, secretion, and function during exocytosis and endocytosis. Moreover, the individual components of the complex are thought to act on specific biological processes, such as cytokinesis, ciliogenesis, apoptosis, autophagy, and epithelial‐mesenchymal transition (EMT). As a result, recent studies suggest that the exocyst complex may be involved in several diseases such as kidney disease, neuropathogenesis, diabetes, and cancer. In this review, we focus on the diverse functions and cellular signaling pathways of the exocyst complex in various tumors. J. Cell. Physiol. 232: 939–957, 2017. © 2016 Wiley Periodicals, Inc. Exo70 interacts strongly with the Sec10–Sec15 subcomplex and Exo84 interacts with the Sec10–Sec15–Exo70 subcomplex. Sec3, Sec5, Sec6, and Sec8 form a tight quaternary subcomplex and Sec8 interacts with Sec10. Each component of the exocyst complex contributes to cancer progression and survival in diverse ways such as break of cell–cell contact, EMT, cell cycle progression, DNA repair, migration, autophagy, and anti‐apoptosis.