Despite common perception as lovable pets or actors, in the wild, male chimpanzees are very aggressive. They often attack each other, frequently hunt other primates, occasionally kill adult chimpanzees and cannibalize infants. In this talk, I describe the underlying hormonal correlates of these aggressive behaviors in an unusually large community of chimpanzee from Kibale National Park, Uganda. The common occurrence and variety of these aggressive behaviors provide unique opportunities to ask multiple questions about hormones and behavior. Are all types of aggression associated with elevated testosterone? What is the relationship between testosterone and meat sharing? Are territorial encounters more ‘stressful’ than hunts? How can hormones help us understand the anticipation of aggression? My observations of territoriality, hunting and meat sharing, linked with the insight hormones provide, increase our understanding of our closest living relatives, chimpanzees.