Latar belakang: Sanitasi lingkungan di pondok pesantren memainkan peran penting dalam menjaga kesehatan santri, dimana lingkungan dengan kepadatan tinggi memiliki prevalensi penyakit menular tinggi khususnya diare. Namun, fasilitas sanitasi yang tidak memadai dapat menyebabkan risiko kesehatan dan penurunan kualitas hidup. Penelitian ini bertujuan untuk menganalisis persepsi santri terhadap kualitas sanitasi lingkungan di Pondok Pesantren An Najah Purwokerto.Metode: Studi cross-sectional ini dilakukan pada 127 siswa dengan menggunakan pendekatan teknik total sampling. Data dikumpulkan menggunakan kuesioner terstruktur yang mencakup lima aspek sanitasi lingkungan: ketersediaan air bersih, fasilitas toilet, pembuangan limbah cair, pengelolaan limbah padat, dan kepadatan penghuni. Statistik deskriptif, meliputi distribusi frekuensi dan persentase, digunakan untuk menganalisis karakteristik responden dan hasil persepsi.Hasil: Mayoritas responden adalah perempuan (88,2%), berusia ≤19 tahun (48,0%), dan lama mondok 1-3 tahun (48,8%). Secara keseluruhan, persepsi santri memiliki nilai rerata baik pada pengelolaan limbah cair (90,1%), ketersediaan air bersih (82,1%), pengelolaan limbah padat (80,9%), dan toilet (80,3). Sedangkan, persepsi kepadatan hunian rendah memiliki nilai cukup besar dengan 40,2%.Simpulan: Persepsi santri terhadap kualitas lingkungan di pondok pesantren baik, khususnya pada pengelolaan limbah cair, ketersediaan air bersih, pengelolaan limbah padat, dan toilet. Meskipun persepsi terhadap kepadatan hunian rendah sehingga perlu adanya peningkatan fasilitas asrama untuk santri untuk mengurangi kepadatan hunian. ABSTRACTTitle: An Analysis of Students’ Perceptions of Environmental Sanitation Quality at An Najah Islamic Boarding School, PurwokertoBackground: Environmental sanitation in Islamic boarding schools (pesantren) plays a crucial role in safeguarding student health, particularly in high-density settings that the incident of communicable disease is prevalent. However, inadequate sanitation facilities may lead to health risks and reduced quality of life. This study was aimed to analyze students’ perceptions of environmental sanitation quality at Pondok Pesantren An Najah, PurwokertoMethod: A cross-sectional survey was conducted on 127 students using a total sampling approach. Data were collected using a structured questionnaire covering five aspects of environmental sanitation, namely availability of clean water, toilet facilities, liquid waste disposal, solid waste management, and population density. Descriptive statistics, including frequency distributions and percentages, were used to analyze respondent characteristics and perception results.Result: The majority of respondents were female (88.2%), aged ≤19 years (48.0%), and had been at the boarding school for 1-3 year (48.8%). Overall, students’ perceptions had good average scores for liquid waste management (90.1%), clean water availability (82.1%), solid waste management (80.9%), and toilets (80.3). Meanwhile, perceptions regarding low housing density had a relatively high score of 40.2%.Conclusion: Boarding school students’ perceptions of environmental quality at the boarding school are positive, particularly regarding wastewater management, clean water availability, solid waste management, and toilets. However, perceptions of housing density are low, indicating a need to improve dormitory facilities for students to reduce housing density.