Gizi buruk yang merupakan masalah penting di semua negara-negara miskin dan berkembang bertanggung jawab terhadap 60 persen kematian balita. Prevalensi balita gizi buruk di Indonesia tergolong tinggi, pada 2005, berbagai propinsi di Indonesia melaporkan 76.178 balita mengalami gizi buruk. Kasihan adalah salah satu kecamatan di kabupaten Bantul berbatasan dengan Kotamadya Yogyakarta yang menghadapi permasalahan gizi buruk. Tujuan penelitian adalah mengetahui angka kejadian dan faktor risiko gizi buruk di Kecamatan Kasihan, Kabupaten Bantul. Penelitian ini menggunakan desain studi kasus kontrol meliputi kelompok kasus 54 balita malnutrisi dan kelompok kontrol 54 balita gizi baik. Status gizi ditentukan berdasarkan Z score berat badan menurut umur. Hasil penelitian menunjukkan bahwa tingkat pendidikan ibu yang tinggi (OR = 0,4 ; 95% CI = 0,19 - 0,79), jarang kelahiran lebih dari 60 bulan (OR = 0,3; 95% CI = 0,11 - 0,90), berat lahir normal (OR = 0,2; 95% CI = 0,10 - 0,60), dan riwayat penyakit kronis (OR = 0,3; 95% CI = 0,14 - 0,80) merupakan faktor protektif malnutrisi pada balita. Malnutrisi tidak berhubungan dengan umur ibu, paritas, tingkat pendidikan ayah, pendapatan keluarga, riwayat ASI, anggota keluarga yang merokok dan imunisasi campak.Malnutrition is one of the leading causes of morbidity and mortality in children under five years of age in developing countries. Malnutrition significantly increases the risk of infant and child death. Although the incidence of malnutrition in Yogyakarta lower than other provinces in Indonesia, the prevalence of severe malnutrition of children under five years of age was 1.14%. the objective of this study were to identify and determine the risk factors for malnutrition in children under the five years of age in Kasihan 1, Bantul District. Case control design was conducted among 54 children under the age of five with malnutrition (z score <-2 Deviation Standart) and 54 comparison children from Kasihan 1. The data were collected using structured questionnaire. The children’s weight and length were measured using standardized and calibrated device. Nutrition state classified using Z score (weight for age) Anthropometry WHO software version 2011. The protective factors for malnutrition were high maternal education (OR = 0.4 ; 95% CI = 0.19 - 0.79), birth space more than 60 months (OR = 0.3; 95% CI = 0.11- 0.90), normal birth weight (OR = 0.2; 95% CI = 0.10 - 0.60), and no history of chronic disease (OR = 0.3; 95% CI = 0.14 - 0.80). There are no relationship between malnutrition with maternal age, parity, paternal education, income, history of breastfeeding, smoking member of family and measles immunization.