Tuna is a global commercial fish and has been marketed as food products. The production of food products from tuna yield a large amount of by-products such as head, bones and liver that can be processed into fish oil production. Fish oil has been applied as food ingredient in the functional food products. However, these products are more prone to oxidation due to the high polyunsaturated fatty acids content in the fish oil. Physicochemical characterisation, oxidative stability and thermal properties of liver oils extracted from two tuna species, namely Longtail tuna (Thunnus tonggol) and Kawakawa tuna (Ethyunnus affinis) were investigated in this study. The major fatty acid in both Longtail tuna liver oil (LLO) and Kawakawa liver oil (KLO) was saturated fatty acid (40.67-41.01%), followed by polyunsaturated fatty acids (37.00-38.91%) and monounsaturated fatty acids (20.00-20.07%). Docosahexaenoic acid (DHA) was the highest fatty acid found in both tuna liver oils (29.41-28.73%). The KLO was more lightness in colour compared to LLO. The peroxide value and p-anisidine value of LLO were 9.20 meq/kg and 5.88, respectively and were not significantly different from KLO (8.13 meq/kg and 4.49, respectively). Melting and crystallisation profiles of the LLO were similar to KLO, which was related to their fatty acid content.