Macroautophagy (hereafter referred to as autophagy) is a lysosomal catabolic pathway whereby cells recycle macromolecules and organelles. The capacity of autophagy to maintain cellular metabolism under starvation conditions and to remove damaged organelles under stress conditions improves the survival of cells. Yet, autophagy appears to suppress tumorigenesis. In this review we discuss recent data that begin to elucidate the molecular basis for this apparent controversy. First, we summarize our current knowledge on the autophagy-mediated control of both cell survival and cell death in general. Then, we highlight the common cancer-associated changes in autophagy induction, regulation and execution. And finally we discuss the potential of pro- as well as anti-autophagic signaling pathways as targets for future cancer therapy.