Abstract. Pharyngitis is inflamation of the pharynx caused by many organisms. including the bacterium Streptococcus pyogenes. Streptococcal pharyngitis if not treated properly can cause serious complications such as rheumatic fever and poststreptococcal glomerulonephritis. Traditional medicines made from herbs have become a culture for the people of Indonesia in an effort to maintain health, one of the plants that is believed to have benefits as an herbal plant is pineapple. This study aims to determine the antibacterial effectiveness of pineapple juice (Ananas comosus L) against Streptococcus pyogenes. The study was conducted by laboratory experimental methods in vitro. The object of the research was the Streptococcus pyogenes bacterial culture collection from the Integrated Laboratory of Health Polytechnic Bandung. Testing the antibacterial effect in this study using the disc diffusion method and the dilution method to determine the inhibitory zone, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The results showed the average diameter of the inhibitory zone of pineapple juice from 100% concentration was 9.80 millimeter. The results of testing the minimum inhibitory consentration and minimum bactericidal concentration of pineapple juice by 50%. It can be concluded that the juice of pineapple fruit pulp (Ananas comosus L) has an antibacterial effect on the bacteria Streptococcus pyogenes.Keywords: juice of pineapple fruit pulp, (Ananas comosus L), antibacterial effect, Streptococcus pyogenesAbstrak. Faringitis merupakan peradangan pada faring yang disebabkan oleh banyak organisme, diantaranya bakteri Streptococcus pyogenes. Faringitis Streptococcal jika tidak ditangani dengan benar dapat menimbulkan komplikasi yang serius seperti rheumatic fever dan post streptococcal glomerulonephritis. Obat tradisional berbahan herbal telah menjadi budaya bagi masyarakat Indonesia sebagai upaya untuk menjaga kesehatan, salah satu tanaman yang dipercaya memiliki manfaat sebagai tanaman herbal adalah nanas. Penelitian ini bertujuan untuk mengetahui efektivitas antibakteri air perasan daging buah nanas (Ananas comosus L) terhadap bakteri Streptococcus pyogenes. Penelitian dilakukan dengan metode eksperimental laboratorium secara in vitro. Objek penelitian merupakan biakan bakteri Streptococcus pyogenes koleksi Laboratorium Terpadu Politeknik Kesehatan Bandung. Pengujian efek antibakteri dalam penelitian ini menggunakan metode difusi cakram dan metode dilusi untuk menentukan zona hambat, KHM dan KBM. Hasil penelitian didapatkan rata-rata diameter zona hambat air perasan daging buah nanas konsentrasi 100% adalah 9,80 mm. Hasil pengujian konsentrasi hambat minimum dan konsentrasi bunuh minimum air perasan daging buah nanas sebesar 50%. Dapat disimpulkan bahwa air perasan daging buah nanas (Ananas comosus L) memiliki efek antibakteri terhadap bakteri Streptococcus pyogenes.Kata kunci: Air perasan daging buah nanas, (Ananas comosus L), Efek antibakteri, Streptococcus pyogenes