Abstrak Latar Belakang. Angka kejadian stunting di Kecamatan Kalasan pada tahun 2018 sebesar 17,01%, nilai tersebut masih jauh dari target penurunan stunting di Kabupaten Sleman yaitu 10%. Penelitian ini bertujuan untuk mengetahui hubungan antara sanitasi penyediaan air bersih dengan kejadian stunting pada balita di Desa Tamanmartani. Metode. Penelitian ini menggunakan metode analitik dengan pendekatan kasus kontrol. Teknik pengambilan sampel menggunakan total sampling.  Sampel penelitian ini adalah ibu yang memiliki balita, yaitu 45 kasus dan 45 kontrol. Instrumen diadaptasi dari formulir inspeksi sanitasi penyediaan air bersih dari Dinas Kesehatan Daerah Istimewa Yogyakarta. Analisis data menggunakan uji Chi-square. Hasil. Hasil penelitian ini menunjukkan ada hubungan signifikan antara sanitasi penyediaan air bersih dengan kejadian stunting (p=0,047, OR=2,705) Penutup. Disarankan bagi masyarakat perlu membersihkan area sekitar sumur gali/ledeng dari kotoran hewan ternak dan sampah, menghindari genangan air serta perbaikan retakan sekitar sumur. Abstract. Background. Stunting incidence at Kalasan District in 2018 was 17.01%, this value is still far from the target for reducing stunting in Sleman Regency, which is 10%. This study aims to determine the relationship between sanitation of clean water supply and the incidence of stunting in children under five in Tamanmartani Village. Method. This study uses an analytical method with a case-kontrol approach. The sampling technique used was total sampling. The sample of this study were mothers who had toddlers aged 0-59 months, there were 45 cases and 45 kontrols. The instrument adapted from the clean water supply sanitation inspection form from Yogyakarta Special Region Health Office. Data analysis using Chi-square test. Results. The results of this study indicate that there is a significant relationship between sanitation of clean water supply and the incidence of stunting (p = 0.047, OR = 2.705). Closing. It is recommended for the community to clean the area around the dug wells from livestock manure and garbage, avoid puddles of water and repair cracks around the well.