ABSTRAK Uji aktivitas antibakteri ekstrak etanol daging dan kulit buah pisang klutuk muda (Musa balbisiana Colla BB) terhadap bakteri Staphylococcus aureus dan Escherichia coli telah dilakukan untuk mengetahui aktivitas ekstrak etanol daging dan kulit buah pisang klutuk muda dalam menghambat pertumbuhan bakteri tersebut. Ekstrak dari sampel diperoleh melalui metode maserasi dengan pelarut etanol 96%. Simplisia daging dan kulit buah masing-masing mengandung kadar air sebesar 5% dan 7,17%, kadar abu total 14,55% dan 11,61%, kadar sari larut air 10,67% dan 9,67%, dan kadar sari larut etanol 9,67% dan 9,67%. Ekstrak etanol daging buah dan kulit buah masingmasing mengandung kadar air sebesar 28,26% dan 15,5%, kadar abu total 10,16% dan 14,09%, kadar sari larut air 33,33% dan 71,67%, dan kadar sari larut etanol 69,16% dan 78,33%. Hasil uji fitokimia menunjukkan bahwa kedua ekstrak mengandung senyawa alkaloid, flavonoid, tanin, triterpenoid dan saponin. Uji aktivitas antibakteri ekstrak etanol sampel dilakukan dengan menggunakan metode sumuran dengan variasi konsentrasi ekstrak yaitu 5; 10; 20; 30 dan 40%. Aktivitas antibakteri terhadap S. aureus pada ekstrak etanol kulit buah lebih tinggi dibandingkan dengan aktivitas ekstrak etanol daging buah. Sedangkan aktivitas antibakteri terhadap bakteri E. coli menunjukkan ekstrak etanol daging buah memiliki aktivitas lebih baik. Aktivitas tertinggi ekstrak etanol kulit buah terhadap S. aureus diperoleh pada konsentrasi 10% dengan zona hambat 9,3 mm dan aktivitas tertinggi ekstrak etanol daging buah terhadap E. coli diperoleh pada konsentrasi 20% dengan zona hambat 8,63 mm. Kata kunci: Buah pisang klutuk muda, Musa balbisiana Colla BB, Ekstrak etanol, antibakteri. ABSTRACT Antibacterial activity test of ethanol extract from flesh and peel of unripe klutuk banana fruit (Musa balbisiana Colla BB) towards bacterial of Staphylococcus aureus and Escherichia coli has been conducted to know the activity of ethanol extract from flesh and peel of unripe klutuk banana fruit in inhibiting the growth of those bacterials. The extract of the samples were obtained through maceration method by ethanol 96% as a solvent. Flesh and peel of fruit simplicial characterization contains water content of 5% and 7,17%, total ash content of 14,55% and 11,61%, water soluble extract content of 10,67% and 9,67%, and ethanol soluble extract content of 9,67% and 9,67%. Ethanol extract from flesh and peel of unripe klutuk banana fruit contains water content of 28,26% and 15,5%, total ash content of 10,16% and 14,09%, water soluble extract content of 33,33% and 71,67%, and ethanol soluble extract content of 69,16% and 78,33%. Phytochemical test showed that both of extract contained alkaloid compounds, flavonoids, tannins, triterpenoids and saponins. Antibacterial activity test of ethanol extract from samples was conducted using a well diffusion method with variation of extract concentrations of 5; 10; 20; 30 and 40%. Antibacterial activity towards bacterial of S. aureus at ethanol extract from peel of fruit activity is higher than activity of ethanol extract from flesh of fruit. While antibacterial activity towards bacterial of E. coli from flesh of fruit showed better activity. The highest activity of ethanol extract from peel of fruit towards S. aureus were obtained at 10% concentration with inhibiting zone diameter of 9,3 mm and the highest activity from ethanol extract from flesh of fruit towards E. coli were obtained at 20% concentration with inhibiting zone diameter of 8,63 mm. Keywords: Unripe Klutuk banana fruit, Musa balbisiana Colla BB, ethanol extract, antibacterial.