Objective: The seeds of Lansium sp. are considered as waste and often discarded. However,it can be used as an alternative source of nutrients if processed properly. To date no data is available on the nutritional composition of exotic Malaysian fruit seeds especially Lansium species. Therefore, the present work explores the benefits of Lansium seeds by assessing their fatty acids and phytochemical compositions. Methods: The oil content and fatty acid composition of total lipids (TLs) and the main lipid classes present in the seeds of three species of Lansium fruits (Lansium domesticum Corr) namely duku, duku langsat and langsat were determined by capillary gas chromatography mass spectrometry (GC-MS) analysis. In addition, the distributions of fatty acids triacylglycerols (TAGs) in the seeds were determined through hydrolysis with pancreatic lipase. The lipid classes/subclasses; (MAGs―monoacylglycerols, DAGs―diacylglycerols, FFAs― free fatty acids and TAGs) were separated using thin-layer chromatography and subjected to high performance liquid chromatography (HPLC) analysis for identification. Results: Results showed, the seeds rich in fat (22.40~24.90 g/100 g) with high amounts of saturated fatty acids (SFAs) ranging from 19.71% (Duku) to 60.33% (Langsat) and Unsaturated fatty acids (USFAs) ranging from (42.46% (Duku) to 73.11% (Duku Langsat). The fatty acid compositions of the TAG fractions were practically identical to the profiles of TLs, with the same dominating fatty acids in both analyzed species. FFAs were characterized by high proportions of SFAs and USFAs. The sn-2 position of TAGs was esterified predominantly with linoleic acid (21.21% ;Duku Langsat) and Oleic acids (62.88%;Langsat) Conclusion: In conclusion, it showed that seeds of Lansium Sp. highly potential to become a source of natural edible fat and exhibit functional benefits. The high nutritional values, coupled with high contents of fatty acids suggest that the seeds of Lansium Sp. is suitable to become a source of healthy oil and used in the production of functional foods.