The genetics of seed longevity was investigated through breeding in soya bean (Glycine max L. Merrill). Three generations, F1, F2, and F3 of Kalitur x PK 416, Kalitur x PK 472, and PK 515 x Ankur crosses were evaluated for seed longevity after eight months of storage under ambient conditions. Of the parental lines, Kalitur and Ankur were of superior seed longevity while PK 416, PK 472, and PK 515 were of poor seed longevity. Seeds from F1 plants (F2 seeds) showed low storability to be dominant over high storability. Segregation pattern in the F2 was 3:1 in Kalitur x PK 472 and 15:1 in Kalitur x PK 416 and PK 515 x Ankur (low vs high storability) suggesting that the trait was governed by one and two major genes, respectively. This ratio was supported by 5:3 and 55:9 ratio in the F3 (bulk) of the respective crosses. This was also confirmed by observing the F3 rows breeding true for the recessive phenotype (i.e., high seed longevity). It is suggested that soya bean seed longevity could be improved by individual plant selection in the early segregating generations.