The impact assessment of an agricultural technology is a complex process of identifying the consequences of its commercialization, dissemination, multiplication and active adoption on a large scale by the end users. Many agricultural engineering technologies generate two kinds of benefits: reduction in cost of operation by virtue of decreasing time required for operation and saving in input and labour engagement, as well as increase in productivity due to the timeliness and uniform quality of farm operations. The present study attempted to estimate the impact of the adoption of Ambika rice (paddy) weeder for conducting weeding operations in line-sown rice on the economy of Chhattisgarh state in India. The economic surplus methods for assessing the impact of agricultural research was adopted for estimating the benefits attained by rice farmers, millers/processors, retailers and consumers. The study revealed that a net present worth of about  6450 crore ( 64500 million) was realized from the adoption of Ambika rice weeder for weeding in line-shown rice fields whereas, other associated stakeholders like millers/processors, rice retailers etc. earned a gross income of about   515 crore (5150 million) from the processing and value addition of surplus rice produced due to adoption of the technology. The aggregate economic impact was about  6965 crore (69650 million) as per  2011-12 prices for the period of 2012-13 to 2019-20 due to adoption of Ambika rice weeder by rice farmers in Chhattisgarh.