Telah dilakukan penelitian tentang uji aktivitas ekstrak etanol daun pepaya (Carica papaya L.) terhadap peningkatan trombosit pada mencit jantan (Mus musculus) yang diinduksi kloramfenikol. Penelitian ini bertujuan untuk mengetahui efek ekstrak etanol daun pepaya serta dosis efektifnya dalam meningkatkan jumlah trombosit pada mencit jantan yang diinduksi kloramfenikol. Pada penelitian ini dilakukan perlakuan pertama pemberian pakan selama 14 hari, perlakuan kedua dengan pemberian kloramfenikol dosis 30mg/30g BB peroral selama 7 hari dan pakan standar selama 7 hari, perlakuan ketiga pemberian kloramfenikol dosis 30mg/30g BB peroral dan ekstrak etanol daun pepaya 1,5% selama 7 hari, perlakuan keempat pemberian kloramfenikol dosis 30mg/30g BB peroral dan ekstrak etanol daun pepaya 3% selama 7 hari. Hasil penelitian menunjukkan bahwa ekstrak etanol daun pepaya menunjukkan efek dalam meningkatkan jumlah trombosit pada mencit jantan yang diinduksi kloramfenikol.Research has been conducted on the activity test of ethanol extract from papaya leaves (Carica papaya L.) on increasing platelet count in male mice (Mus musculus) induced with chloramphenicol. The purpose of this study was to determine the effect of ethanol extract from papaya leaves and its effective dosage in increasing platelet count in male mice induced with chloramphenicol. In this study, the first treatment involved feeding for 14 days, the second treatment involved administering chloramphenicol at a dose of 30mg/30g body weight orally for 7 days along with standard feed for 7 days, the third treatment involved administering chloramphenicol at a dose of 30mg/30g body weight orally along with 1.5% ethanol extract of papaya leaves for 7 days, and the fourth treatment involved administering chloramphenicol at a dose of 30mg/30g body weight orally along with 3% ethanol extract of papaya leaves for 7 days. The results showed that the ethanol extract of papaya leaves exhibited an effect in increasing platelet count in male mice induced with chloramphenicol.