This study was aimed to determine the effect of fish oil addition on growth performance and fatty acid composition of eel Anguilla bicolor bicolor. Freswater eel at an initial body weight of 9.90± 0.05 g were maintained in aquarium with volume of 120 L at stocking density of 1 g/L for 40 days. This research applied complete randomized design with four treatments addition of fish oil, i.e. 0%, 5%, 10%, and 15%. All treatments were carried out in triplicate. Feed given as much as 3% of the fish biomass a day for four times at 06:00, 11:00, 16:00, and 21:00. The results showed that the addition of fish oil in the diet have different effects (P0.05) at 100%. In the fatty acid composition total of unsaturated fatty acid composition was 30.91–40.95%, n-3 fatty acids was 6.10–8.19%, and n-6 fatty acids were 6.18–8.19%. In conclusion, the addition of fish oil in the diet of freshwater eel Anguilla bicolor bicolor can be done up to 5% (13% fat content of diet). Keywords: Anguilla bicolor bicolor, fish oil, growth performance, fatty acid composition ABSTRAK Penelitian ini bertujuan untuk menguji pengaruh penambahan minyak ikan terhadap kinerja pertumbuhan dan komposisi asam lemak ikan sidat Anguilla bicolor bicolor. Ikan sidat dengan bobot 9,90±0,05 g dipelihara dalam akuarium dengan volume 120 L pada padat tebar 1 g/L selama 40 hari. Penelitian ini menggunakan rancangan acak lengkap terdiri atas empat perlakuan penambahan minyak ikan pada pakan sebesar 0%, 5%, 15%, dan 15%. Semua perlakuan terdiri atas tiga ulangan. Pakan diberikan sebanyak 3% dari biomassa ikan dan diberikan sebanyak empat kali sehari yaitu pukul 06.00, 11.00, 16.00 dan 21.00. Hasil penelitian menunjukkan bahwa penambahan minyak ikan dalam pakan memberikan pengaruh yang berbeda (P0,05) yaitu 100%. Pada komposisi asam lemak dihasilkan total komposisi asam lemak tidak jenuh 30,91– 40,95%, asam lemak n-3 6,10–8,19%, dan asam lemak n-6 6,18–8,19%. Dengan demikian, dapat disimpulkan bahwa penambahan minyak ikan dalam pakan ikan sidat Anguilla bicolor bicolor dapat dilakukan sampai dengan 5% (kadar lemak pakan 13%). Kata kunci: Anguilla bicolor bicolor, minyak ikan, kinerja pertumbuhan, komposisi asam lemak