AbstrakMasalah penelitian adalah faktor-faktor apakah yang berhubungan dengan status gizi underweight pada balita. Tujuan penelitian untuk mengetahui faktor-faktor yang berhubungan dengan status gizi underweight pada balita. Metode penelitian survei pada balita umur 7-59 bulan di wilayah Puskesmas Leuwimunding sebanyak 200 sampel, menggunakan cluster random sampling. Pengambilan data dengan wawancara dan pengukuran berat badan secara langsung menggunakan alat ukur dacin. Analisis data menggunakan chi square. Hasil penelitian menunjukkan balita yang tergolong status gizi underweight sebanyak 31,40 %, yang mengalami diare kronik 14,90 %, dan pneumonia 8,80 %. Praktik pemberian makan anak balita tergolong kurang baik sebanyak 43,80 %, praktik pengobatan anak balita tergolong kurang baik sebanyak 25,30 %, dan praktik kesehatan anak balita tergolong kurang baik sebanyak 41,80 %. Tingkat konsumsi energi kurang baik pada anak balita sebanyak 60,30 %, dan tingkat konsumsi protein kurang baik pada anak balita 54,60 %. Simpulan penelitian, faktor yang berhubungan dengan status gizi buruk pada balita umur 7-9 bulan yaitu pola asuh pemberian makan balita, tingkat konsumsi energi, dan protein balita.The research problem was whether the factors associated with underweight nutritional sta-tus in children under five. Research purpose to determine the factors associated with under-weight nutritional status in toddler. Survey method in infants aged 7-59 months in the re-gion of Leuwimunding health center amounts 200 samples, using cluster random sampling. Data collected by interview and direct weight measurement using bathroom scales. Data analysis by chi square. The results showed the nutritional status of toddler were classified as underweight as 31.40 %, which was experiencing chronic diarrhea 14.90% and pneumonia 8.80%. Unfavorable practice of toddler feeding as 43.80%, unfavorable treatment practices of toddler as 25.30%, and unfavorable health practices of toddler as unfavorable as 41.80% . The rate of energy consumption is not good for toddler as much as 60.30%, and the rate of protein consumption wass less good in 54.60% of toddler. The conclusions, factors associ-ated with underweight nutritional status in infants aged 7-9 months were toddler feeding, level of energy consumption, and protein toddlers.