Pancreatic stellate cells (PSCs) change from a quiescent to activated state in the tumor environment and secrete extracellular matrix (ECM) molecules and cytokines to increase the aggressiveness of tumors. However, it is not clear how PSCs are activated to produce these factors, or whether this process can be inhibited. PSCs have morphological and functional similarities to hepatic stellate cells, which undergo autophagy to promote fibrosis and tumor growth. We investigated whether autophagy activates PSCs, which promotes development of the tumor stroma and growth of pancreatic tumors in mice.