Abstrak. Tujuan penelitian ini adalah untuk mengetahui pengaruh substitusi sebagian ransum komersil periode finisher dengan tepung kulit pisang fermentasi + bungkil kelapa + minyak sawit + feed supplement terhadap efisiensi ekonomis pemeliharaan itik peking. Penelitian dilakukan di Laboratorium Lapangan Peternakan (LLP), Program Studi Perternakan, Fakultas Pertanian, Universitas Syiah Kuala tanggal 22 Februari‒19 April 2017. Penelitian menggunakan 100 ekor anak itik peking produksi PT Charoen Pokphand, Medan. Rancangan yang digunakan adalah Rancangan Acak Kelompok (RAK), terdiri dari 4 perlakuan dan 4 kelompok. Tiap kelompok merupakan unit percobaan, masing-masing terdiri dari lima ekor itik. Perlakuan yang dicobakan adalah pemberian tepung kulit pisang fermentasi sebanyak 0, 4, 8, dan 12%. Hasil penelitian memperlihatkan substitusi ransum komersil dengan tepung kulit pisang fermentasi + bungkil kelapa + minyak sawit + feed supplement selama periode finisher menurunkan biaya ransum dan menaikkan IOFC dan total income. Ransum komersil paling layak dan menguntungkan jika disubstitusi dengan 8% tepung kulit pisang fermentasi + 5% bungkil kelapa + 1% minyak sawit + 1% feed supplement selama periode finisher. Kata Kunci: itik, income, kulit pisang fermentasi Effect of Feeding Fermented Banana (Musa sp) Peel Meal as Partial Substitution of Commercial Diet to Economic Efficiency of Raising Peking DucksAbstract. The aim of present study was to determine effect of substitution commercial diet with fermented banana peel meal + coconut meal + coconut oil to economic efficiency of raising duck during grower/finisher period. The study was conducted in Field Laboratory of Animal Husbandry, Livestock Department, Faculty of Agriculture, Syiah Kuala University, February 22 until April 19, 2017.The study used 100 Peking DOD males, produced by PT Charoen Pokphand, Medan. The study was performed into block randomized design with subsamples, consisting of 4 treatments and 4 blocks. Each block was an experimental unit, each consisting of five ducks. The treatment was inclusion of fermented banana peel meal as many as 0% (P1), 4(P2), 8% (P3), and 12% (P4), respectively. Results of study showed that inclusion of fermented banana peel meal + coconut meal + coconut oil as partial substitution of commercial duck diet during grower/finisher periode reduced cost and increased IOFC as well as total income. It was suggested that the best level of substitution of finisher commercial diet was 8% fermented banana peel meal + 5% coconut meal + 1% coconut meal + 1% feed supplement.Key words: duck, banana peel, fermentation, income