Soybean is an important oilseed crop in India and varieties with high yield potential are being developed since 1969. This study was conducted to assess the impact of breeding on yield and plant characteristics during the last 25 years. A 3-year field experiment was conducted to evaluate forty three soybean varieties belonging to two different selection cycles and representing most of the varieties developed in the domestic breeding programme of India from 1969 to 1993. Varieties resulting from selection cycle 1 showed 4 times higher seed yield and harvest index as compared to the farm traditional variety Kalitur. This yield increase was due to an increase in biomass, pods plant−1, mean seed weight and longer seed filling duration, but a reduced plant height and improved lodging tolerance, less seeds pod−1 and early flowering and maturity dates. The varieties of selection cycle 2 showed 19% higher seed yields and 16% increase in harvest index over selection cycle 1 accompanied by longer seed filling duration, more seeds pod−1 and reduced plant height. The annual genetic gain in seed yield of soybean varieties released in India from 1969 to 1993 was approximately 22 kg ha−1.