Abstrak Latar Belakang :Stunting atau biasa disebut tubuh pendek dapat diartikan sebagai kondisi dimana terjadi gangguan pertumbuhan pada anak dibawah usia 5 tahun akibat dari kurangnya asupan gizi terutama dalam seribu (1000) hari pertama kehidupan. Stunting dapat dipengaruhi oleh berbagai faktor antara lain pengetahuan ibu dan dukungan keluarga. Tujuan penelitian ialah untuk mengetahui hubungan antara pengetahuan ibu dan dukungan keluarga dengan upaya pencegahan stunting pada balita di Posyandu Anggrek 1 RW 06 Kramat Jati, Jakarta Timur Metode : Desain penelitian yang digunakan adalah Cross Sectional dan pengambilan sampel dilakukan dengan propotional stratified simpel random pada 96 sampel ibu balita. Pengumpulan data menggunakan kuesioner yang terdiri dari karakteristik responden ibu dan anak, pengetahuan ibu, dukungan keluarga dan upaya pencegahan stunting yang sudah dilakukan validitas dan reabilitas. Hasil : Uji analisis statistik didapatkan hasil terdapat hubungan pengetahuan ibu (P=0,004) dan dukungan keluarga (P=0,031) dengan upaya pencegahan stunting pada balita. Kesimpulan: Terdapat hubungan yang bermakna antara pengetahuan ibu dan dukungan keluarga dengan upaya pencegahan stunting pada balita. Disarankan pemberian edukasi tentang stunting kepada ibu dan meningkatkan upaya dukungan keluarga dapat dilakukan sebagai bentuk upaya preventif kejadian stunting. Kata Kunci: Balita, Dukungan keluarga, Pencegahan stunting, Pengetahuan Abstract Background: Stunting or commonly called short body can be interpreted as a condition where there is a growth disorder in children under the age of 5 years due to lack of nutritional intake, especially in the first thousand (1000) days of life. Stunting can be influenced by various factors, including mother's knowledge and family support Methods: The purpose of the study was to determine the relationship between mother's knowledge and family support with efforts to prevent stunting in toddlers at the Orchid 1 Posyandu, RW 06, Kramat Jati, East Jakarta. The research design used was cross sectional and the sampling was done by proportional stratified simple random on 96 samples. Data collection using a questionnaire consisting of the characteristics of the respondents mother and child, mother's knowledge, family support and stunting prevention efforts that have been carried out validity and reliability. Results: The statistical analysis test showed that there was a relationship between mother's knowledge (P = 0.004) and family support (P = 0.031) with efforts to prevent stunting in toddlers. Conclusion: Based on the results of the study, it was concluded that there was a significant relationship between mother's knowledge and family support and efforts to prevent stunting in toddlers. The author suggests the importance of providing education about stunting to mothers and increasing family support efforts to prevent stunting in toddlers. Keywords: Family support, Knowledge, Stunting prevention, Toddler