In research settings in the Eastern Gangetic Plain, Conservation Agriculture (CA) reduces operational costs, including cost for machinery, labour and fuel, while increasing yields, profit and soil organic carbon. However, the impact of the CA practices when adopted by smallholder farms on their crop productivity and farm profitability in this region is not well understood. In three locations in Rajshahi and Thakurgaon districts, Bangladesh, where previous on-farm CA research and demonstrations had been focused, we assessed the adoption and impacts of CA technologies on 135 farms compared to 270 non-adopters. While the CA technology adoption is still ongoing in the study areas, those farmers who practiced CA technology decreased human labour by up to 34%, seed use by 31%, fertilisers by 6%, pesticides by 32%, and total cost of production up to 10% while cultivating lentil, mustard, maize and wheat. The respective increases in crop yield and net profit were up to 28% and 43%, respectively. Propensity score matching (PSM) methods further confirmed that CA technology adoption had significant impacts by increasing crop yield, reducing variable costs, and increasing adopters’ net income. Given the striking on-farm benefits of CA for smallholders in the EGP, programmes to expand the availability of minimum tillage planters, provide training to local service providers on CA methods, and the use of smart incentives should be evaluated to assist farmers to adopt CA seeding machinery and associated agronomic practices.