Urban agriculture (UA) is re-emerging worldwide as a strategy to simultaneously address a diverse array of interrelated urban issues and is of interest to urban sustainability (US) scholars/practitioners. Although the practice has begun to be documented, there is a need for analytical instruments and more systematization. We developed a conceptual framework to assess the contributions that UA can make to US and applied it to the qualitative analysis of UA practices in contemporary San Cristobal de Las Casas (SCLC), Mexico. We found a rich practice (variety of local types of UA; number and diversity of concrete manifestations in four sustainability dimensions), in contrast with many reported cases. The framework proved valuable in evidencing data and stimulating analysis and is likely to be useful for systematized comparisons across sites. We discuss UA limitations and further refinements that can improve the framework's ability to guide action towards increasing the impact of UA on US.