AbstractDeveloping green seeds of two vegetable pigeonpea (Cajanus cajan L Millsp) cultivars that differ in their morphological characteristics were sampled at 24, 26, 28, 30 and 32 days after flowering (dates that are relevant to vegetable harvest). An increase in seed size was noticed between 24 and 26 days after flowering, although it continued up to 32 days after flowering. The dry matter accumulation as the seed matured was greater in ICP 7035 than in T 15–15. Analysis of freeze‐dried samples showed that soluble sugars, and proteins, decreased and starch content increased between 24 and 32 days after flowering. Calcium and magnesium contents were considerably higher in T 15–15 than in ICP 7035, but there was little difference in zinc, iron and copper contents. ICP 7035 contained significantly higher amounts of soluble sugars than T 15–15 at all stages of seed development: this indicates that it had sweet seeds, a requisite of vegetable pigeonpea cultivars.