Belongingness theory proposes that humans possess an innate drive for a minimum number of lasting interpersonal relationships. On geographic relocation, people leave their existing social networks. This greatly threatens belongingness needs, and the authors propose this is one cause of homesickness. Two studies investigated whether homesickness arises in the need to belong. Study 1 used a correlational design to test the relationship between need to belong and homesickness while controlling for other variables. A significant positive relationship was found. Study 2 then used an experimental design to test for a causal effect of need to belong on homesickness, and a significant effect was found. An additional finding showed that individuals who felt accepted in the community were less homesick. This was independent of number of friends and demonstrates an important link between community attitudes and adjustment. Implications for belongingness theory are discussed.