A lot of studies have been done on feeling of crowding. Some of them found a link between feeling of crowding and feeling of insecurity. For example, McCarthy and Saegert (1978) reported that the inhabitants of high rise buildings felt less safe in the semiprivate spaces (Hallway, elevators, ...) of their buildings than low-rise apartment tenants. This feeling of insecurity was correlated to feeling of crowding. These findings are consistent with the concept of defensible space elaborated by Newman (1972). Residential spaces which are difficult to control and which do not facilitate group development among neighbors can provide a feeling of insecurity. In the literature, this lack of control on social interactions and anonymity are also related to the feeling of crowding. The aim of the present paper is the study of the links between perceived density in large residential buildings and feeling of security. The results presented here are a part of an important research on feelings of crowding and crampedness in residential environment.