Abstrak. Penelitian Isolasi dan Identifikasi Jamur Patogen pada Air Sumur di Wilayah Pemukiman Warga RW 05-08 dan Air Sungai Cilaki, Desa Karangwangi, Cianjur, Jawa Barat, bertujuan untuk melihat keanekaragaman jamur patogen yang terdapat pada air sumur RW 05-08 dan air sungai Cilaki. Metode yang digunakan dalam penelitian ini adalah metode deskriptif eksploratif untuk menentukan lokasi pengambilan sampel. Dilakukan pengenceran dari sampel air kemudian dilakukan metode pour plate dengan medium Agar Sabouraud lalu diinkubasi selama 72-96 jam. Koloni jamur dihitung dengan metode Total Plate Count (TPC). Identifikasi dilakukan secara makroskopis dengan melihat bentuk dan warna koloni jamur, serta secara mikroskopis dengan cara moist chamber. Hasil jumlah koloni jamur patogen terbanyak ditemukan pada sumur RW 06. Hasil penanaman seluruh sampel air sumur dan sungai, ditemukan 9 spesies jamur patogen, genus Penicillium sebanyak 2 spesies, Trichophyton sebanyak 3 spesies, Geotrichum sebanyak 2 spesies, Microsporum dan Lichtheimia masing-masing sebanyak 1 spesies. Dari hasil yang didapat, disimpulkan bahwa air sumur di wilayah RW 05-08 dan air sungai Cilaki di Desa Karangwangi kurang baik jika digunakan secara langsung karena banyaknya jamur patogen yang terkandung di dalamnya. Kata Kunci: Jamur, Sumur, Sungai, Total Plate Count. Abstract. Isolation and Identification of Pathogenic Fungi on Well Water Territory Residential Residents RW 05-08 and Cilaki River Water, Karangwangi village, Cianjur, West Java research, aiming to see the diversity of fungal pathogens found in well water RW 05-08 and Cilaki river water. The method used in this study is descriptive exploratory method for determining the location of sampling of water in wells in RW 05 to RW 08 and Cilaki river. Do dilution of water samples and then performed pour plate method with Sabouraud agar medium and incubated for 72-96 hours. Fungal colonies which have grown calculated by the method Total Plate Count (TPC). Identification is done macroscopically by looking at the shape and color of fungal colonies and microscopically by creating a wet media room (moist chamber). The result is the highest number of colonies of pathogenic fungi found in well water samples RW 06. From the planting around the wells and river water samples, found as many as nine species of fungal pathogens, with as many as two species of the genus Penicillium, Trichophyton many as three species, Geotrichum much as 2 species , Microsporum and Lichtheimia each as much as one species. From the results obtained, it can be concluded that water wells in the area RW 05-08 and Cilaki river water in Karangwangi village less well if used directly because of the large number of pathogenic fungi colonies contained there in.Keywords : Pathogenic Fungi, Water, Well, River, Pour Plate, Total Plate Count, Moist Chamber