Peneltian ini dilakukan untuk menggali penyebab rendahnya cakupan ASI eksklusif dan faktor-faktor yang mempengaruhinya di Puskesmas Serpong 1, Kecamatan Serpong, Kota Tangerang Selatan. Informan petugas kesehatan dari puskesmas, rumah bersalin, klinik swasta dan bidan praktek pribadi. Penelitian dilaksanakan pada bulan November-Desember 2016 dengan pendekatan kualitatif dan metode wawancara mendalam. Data utama penelitian ini adalah data primer dilengkapi data sekunder. Data sekunder diambil dari profil puskesmas serpong 1, data primer didapatkan dengan melakukan wawancara mendalam kepada petugas kesehatan, kader posyandu, ibu bayi dan suami/orang tua diwilayah kerja Puskesmas Serpong 1. Hasil penelitian menunjukkan bahwa dukungan petugas kesehatan dan orang tua dengan pemberian ASI eksklusif masih kurang, terutama dalam penatalaksanaan Inisiasi Menyusu Dini dan rawat gabung. Pengetahuan tentang ASI eksklusif dari suami/orang tua dan kader posyandu masih kurang, sehingga diperlukan sosialisasi dan pengawasan terhadap pemberian ASI eksklusif dimasyarakat, penegasan sanksi terkait pelanggaran terhadap ketentuan-ketentuan dalam peraturan terkait pemberian ASI eksklusif. Kata kunci: ASI Eksklusif, Inisiasi Menyusu Dini, Dukungan, Kualitatif This study was conducted to explore the causes of low coverage of exclusive breastfeeding and the factors that influence in the Serpong 1 Community Health Center, Serpong subdistrict, South Tangerang City. Informants Health Officer of Health centers, maternity homes, private clinics and private midwives. The study was conducted in November-December 2016, with a qualitative approach and indepth interviews. Main data of this study are primary data include secondary data. Secondary data was taken from the profile of Serpong 1 Community Health Center, primary data obtained by conducting in-depth interviews indicated to health workers, cadres Posyandu, the baby's mother and husband / parent in the work area Serpong 1 Community Health Center. Research results show that support for health workers and parents with exclusive breastfeeding is still lacking, particularly in the treatment of Early Initiation of Breastfeeding and rooming. Knowledge of exclusive breastfeeding from husband / parents and cadres Posyandu is still lacking, so that the necessary socialization and supervision of exclusive breastfeeding in the community, the affirmation of sanctions related to violations of the provisions of the relevant rules granting exclusive breastfeeding. Keywords: Exclusive breastfeeding, Early Initiation of Breastfeeding, Support, Qualitative