The present study aims to determine the compositional changes including physicochemical characterization of Jatropha seed oil at three different stages of ripening (green: JO‐I; yellow: JO‐II; and brown: JO‐III). The moisture and oil content of Jatropha seeds was 60.83–10.12% and 34–32 (wt%) for JO‐I to JO‐III stages, respectively. The moisture content and acid value (mg KOH/g) of the oil was 8.88–4.05% and 0.62–2.86. Fatty acid composition (wt%) of the oil (JO‐I‐III stage) showed that palmitic (C16:0) acid decreases from 16.98 to 14.40 while as stearic (C18:0) acid increases from 7.19 to 7.57. The content of the monounsaturated acid (wt%) oleic (9‐cis C18:1) acid was 53.13, 41.96, and 60.93, while a diunsaturated acid, linoleic (9‐cis 12‐cis C18:2) acid, was 12.39, 32.52, and 14.93 in the JO‐I to JO‐III stages respectively, which was also confirmed by 1H NMR. The percentage of diunsaturated (9‐cis 12‐cis C18:2) acid follows a reverse trend to the monounsaturated (9‐cis C18:1) acid. The stage JO‐II (yellow) seems to be a turning point in the seed development. The studies also revealed the presence of sterol glucosides in early stage (JO‐I) of seed development; which declined at later stages. The results showed that variation in fatty acid composition together with the physicochemical properties can be helpful in understanding the biosynthesis of seed development.Study describes the compositional changes including physicochemical characterization of Jatropha seed oil at three different stages of ripening (green: JO‐I; yellow: JO‐II; and brown: JO‐III) using integrated analytical techniques (i.e. 1H, 13C NMR, GC).