International discussions on climate change increasingly recognize the importance of agriculture in adaptation and mitigation efforts. Adaptation has been generally prioritized in the most vulnerable countries, where a failure to adapt can constitute a threat to food security. However, synergies between adaptation and mitigation exist in many cases. Climate-smart agriculture, an approach to agriculture that sustainably increases productivity, enhances adaptation and mitigates emissions where possible, is gaining ground. The potential to harness mitigation co-benefits in the IFAD portfolio remains unexploited, potentially leading to unrecognized impact and lost opportunities to access climate finance. This study estimates the mitigation potential of agricultural practices supported by IFAD’s current investments in agricultural development to provide guidance for the design of future IFAD investments. We use data from field studies in the scientific literature to estimate the effects of a large set of agricultural practices promoted by IFAD (and other development agencies) on soil organic carbon stocks, nitrous oxide emissions from soils, and methane emissions from rice paddies. Our findings identify soil and rice management practices with the largest mitigation potential and those that can potentially increase emissions; discuss uncertainties in mitigation analyses; and provide recommendations to improve monitoring of mitigation benefits for project design and implementation.