In the recent past, a growing number of voices within the spatial sciences have called for a departure from traditional economic considerations related to the current market and growth paradigm. Instead, they favour a post-growth economy approach. This can convey the impression that there is an immediate need for action in spatial development policy and planning in terms of providing a stronger post-growth orientation, which has not yet quite managed to establish itself across the board. Against this background and based on the existing trade-off between economic growth and environmental protection, this paper takes a critical look at the post-growth approach by contrasting it with the possibility of green growth. It concludes by considering some implications of this comparative analysis for the spatial sciences and spatial planning.