Autophagy is a ubiquitous cellular process responsible for the bulk degradation of cytoplasmic components through an autophagosomal-lysosomal pathway. Genetic screens, primarily in S. cerevisiae, have identified numerous genes that are essential for autophagy. Many of these genes have orthologs in higher eukaryotes, including C. elegans, Drosophila, and mammals. Gene knockdown/knockout studies in C. elegans have been useful to probe the functions of autophagy in an intact multicellular organism that undergoes development to produce different cell types. This review summarizes important themes that have emerged regarding the roles of autophagy in C. elegans in adaptation to stress, aging, normal reproductive growth, cell death, cell growth control, neural synaptic clustering, and the degradation of aggregate-prone proteins.