Drained peatlands are greenhouse gas (GHG) emission hotspots. Where peatland restoration is not a suitable mitigation option, wet agriculture, i.e., agricultural production with a high water table, may provide an alternative. One possible crop is rice, which is already grown in wet conditions in many parts of the world, but its cultivation is associated with high CH4 emissions. This systematic review aims to quantify whether or not paddy rice cultivation on degraded peatlands is, from the climate perspective, preferable to upland cropping. More specifically, it assesses whether a possible reduction in CO2 (and less importantly N2O) emissions offset the increase in CH4 emissions. Flux measurements from paddy rice cultivation on degraded peatlands were obtained from twelve publications, mostly outside of the tropics. Many studies provided fluxes also from an adjacent upland crop, enabling a direct comparison of fluxes. Across all studies, paddy rice cultivation resulted in on average higher CH4 emissions and significantly lower CO2 and N2O emissions than upland cropping. The combined changes of CH4 and CO2 could be compared for both cropping types in six studies. Five of these showed a reduction in global warming potential associated with paddy rice cultivation and we conclude that paddy rice cultivation of degraded peatlands is preferable, from the climate perspective, to drained cultivation of these soils. Using maps of global paddy rice production and of peatlands, we estimate that this mitigation measure could reduce emissions of degraded peatlands by 16.5 Mt CO2-eq. per year.