On the basis of the literature (produced mainly by sociologists, architects, and geographers) about gated and cohousing communities, this work analyzes how these communities differ from each other. The analysis suggests that cohousing and gated communities are different in the nature of relationships between residents and in the reasons why they arise, even if there are some points of similarity. The risk of a degeneration of cohousing in the gated type is linked in particular with a complete transformation of the grass-roots model (typical of cohousing) to the top-down speculative scheme (typical of gated communities).