AbstrakBelut (Monopterus albus) merupakan biota perairan yang diduga memiliki kandungan asam lemak dan kolesterol yang tinggi. Tujuan penelitian ini adalah untuk membandingkan komposisi kimia, asam lemak, kolesterol serta histologi (struktur jaringan) belut segar dan rebus. Penelitian ini dilakukan dalam beberapa tahapan meliputi pengambilan, preparasi, perhitungan morfometrik dan rendemen sampel, serta perebusan belut (100ºC selama 20 menit). Analisis dilakukan pada belut segar dan rebus yaitu proksimat, asam lemak, kadar kolesterol, dan pengamatan histologi. Asam lemak jenuh (SFA) dominan pada belut segar adalah asam palmitat (13,79%), asam lemak tak jenuh tunggal (MUFA) terbanyak adalah asam oleat (19,45%), asam lemak tak jenuh jamak (PUFA) tertinggi adalah asam linoleat (7,42%). Kandungan asam lemak dan histologi belut berubah akibat proses perebusan. Kandungan kolesterol 60 mg/100 g (belut segar) turun menjadi 56,32 mg/100 g (setelah perebusan).Kata kunci: asam lemak, belut (Monopterus albus), kolesterol, struktur jaringan Abstract Eel (Monopterus albus) is an aquatic biota that have a high nutrient content such as fatty acids and cholesterol. The purpose of this research was to determine the chemical composition, fatty acid, cholesterol, and description of tissue in fresh dan boiled eel. The research was carried out in several steps include sampling, sample preparation, morphometric and yield calculations, boiling eel for 20 minutes at 100ºC. Analysis performed in fresh and boiled eel was proximate analysis, fatty acids, cholesterol, and observation of tissue structure. The highest content of saturated fatty acids (SFA) in fresh eel was palmitic acid 13.79%, the highest content of monounsaturated fatty acid (MUFA) was oleic acid 19.45%, the highest content of polyunsaturated fatty acid (PUFA) was linoleic acid 7.42%. The content of fatty acid and cholesterol in eel has changed overall due to the boiling process. The content of cholesterol were 60 mg/100 g (in fresh eel) and 56.32 mg/100 g (in boiled sample). The structure of eel's tissue changed due the boiling process.