[Peridontitis kronis adalah salah satu penyakit gigi dan mulut dengan prevalensi terbesar di Indonesia . Bakteri utama penyebab periodontitis kronis adalah bakteri black pigmented, yaitu Porphyromonas gingivalis dan Prevotella intermedia. Binahong telah terbukti secara ilmiah memiliki zat antibakteri. Penelitian ini bertujuan untuk membuktikan efek antibakteri infusum daun binahong terhadap bakteri black pigmented. Konsentrasi infusum yang diuji 100%, 95%, 80%, 65%, dan 50%. Uji difusi cakram kertas dilakukan untuk mengetahui zona hambatan menggunakan media agar brucella Dari uji difusi pada media agar brucella didapatkan nilai zona hambatan sebesar : 0,42 mm (50%), 1,21 mm (65%), 1,18 mm (80%), 1,19 mm (95%) dan 1,36 (100%). Infusum daun binahong memiliki daya hambat terhadap pertumbuhan bakteri black pigmented., Chronic Periodontitis is one of the oral disease with highest prevalence in Indonesia. The major periodonthopathogens bacteria in chronic periodontics is black pigmented bacteria, which consist of Porphyromonas gingivalis and Prevotella intermedia. Binahong has been proved scientifically to have antimicrobial substance. This study is aimed to prove that ninahong leaves infusion is effective as an antibacterial agent against black pigmented bacteria in vitro. The concentration of infusion that were used in this test were 100%, 95%, 80%, 65% and 50%. Blank disc diffusion method was performed to measure zone of inhibition in brucella agar. From the diffusion test on brucella agar, the scores of inhibitory zones are : 0,42 mm (50%), 1,21 mm (65%), 1,18 mm (80%), 1,19 mm (95%) dan 1,36 (100%). It is concluded that binahong leaves infusion have inhibition effect on the growth of black pigmented bacteria.]