In the Lake Titicaca Basin during the Late Intermediate period (LIP; AD 1100–1450), people's lives were overwhelmingly structured by warfare. Previous research in the region has shed light on how martial conflict between and possibly among competing ethnic groups motivated people to live in fortified villages on defensive hilltops. At the same time, there was a centuries-long drought that threatened agricultural production. Little is known about the plant use of people living in hillforts during this arduous time. Drawing on macrobotanical information collected from Ayawiri, one of the largest hillforts in the northern Titicaca Basin, I argue that the food stuffs and plants used were locally grown. Additionally, these findings indicate a possible departure from earlier symbolically charged and ritually important plant consumption practices based on the lack of imported maize. This research sheds light on how people adapted their domestic and agricultural strategies to warfare and climate change during the LIP.