The fungicide rapamycin increases lifespan in eukaryotes by interfering with the activity of a serine/threonine kinase called TOR (target of rapamycin). TOR complex 1 (TORC1) is an essential integrator of cellular nutrient cues, growth signals and cellular metabolism. Here, we review major components of TORC1, its downstream effectors and lifespan studies in various organisms involving these signaling components. In particular, we focus on the role of rapamycin in mitochondrial biogenesis, in metabolic regulation and in the control of reactive oxygen species production.