Bitter gourd (Momordica charantia L.) seeds is known to have efficacy in treating skin diseases, one of which is acne. This study aimed to determine the potency of antibacterial activity, minimum inhibitory concentration (MIC) and equality with comparator. The extraction process was carried out by maceration method using ethanol 96%, then fractionation was performed by using liquid-liquid extraction. The antibacterial activity of extract and fractions of bitter gourd seed against Propionibacterium acnes were done by agar diffusion method. The results showed that the extract and other fractions of bitter gourd seeds gave antibacterial activity against Propionibacterium acnes. The extract and three fractions of bitter gourd seeds inhibited the growth of Propionibacterium acnes at concentrations of 40%, 50% and 60%. The value of MIC of the extract was 30% with an 8,9 mm inhibit zone. At concentration of 40%, the fraction of ethyl acetate of bitter gourd seeds gave the highest activity in inhibiting Propionibacterium acnes compared to extract and other fractions. When it is compared with clindamycin as comparison, 1 mg of bitter gourd seed extract is equivalent to 0,80 μg clindamycin. Keywords: Bitter gourd seed, Momordica charantia L., Antibacterial, Propionibacterium acnesABSTRAK Biji pare (Momordica charantia L.) diketahui memiliki khasiat dalam mengobati penyakit kulit, salah satunya jerawat. Penelitian ini bertujuan untuk menentukan potensi aktivitas antibakteri, konsentrasi hambat minimum (KHM) dan kesetaraan dengan pembanding. Proses ekstraksi dilakukan dengan cara maserasi menggunakan pelarut etanol 96%, dilanjutkan dengan fraksinasi menggunakan ekstraksi cair-cair. Aktivitas antibakteri ekstrak dan fraksi biji pare terhadap Propionibacterium acnes dilakukan dengan metode difusi agar. Hasil penelitian menunjukkan bahwa ekstrak dan fraksi biji pare memiliki aktivitas antibakteri terhadap Propionibacterium acnes. Ekstrak dan ketiga fraksi biji pare menghambat pertumbuhan Propionibacterium acnes pada konsentrasi 40%, 50% dan 60%. Nilai KHM dari ekstrak diperoleh 30% dengan zona hambat 8,9 mm. Pada konsentrasi 40%, fraksi etil asetat biji pare memberikan aktivitas paling tinggi dalam menghambat Propionibacterium acnes dibandingkan ekstrak serta fraksi lainnya. Dibandingkan dengan klindamisin, 1mg ekstrak biji pare setara dengan 0,80 µg klindamisin. Kata Kunci: Biji pare, Momordica charantia L., antibakteri, Propionibacterium acnes