Growth monitoring and promotion (GMP) is a prevention activity comprised of growth monitoring linked with promotion/counseling that serves as the core activity in an integrated child health and nutrition programme. However, different methods of institutional studies have shown that the utilization of GM services has remained to be inadequate in various settings of the developing world. There was scarcity of studies conducted including promotion/counseling/ of GM in quantitative method. Therefore, this study was conducted to address the level of GMP services and associated factors among children under to years of age in rural communities of Mareka district, South Ethiopia, 2016. Community based cross-sectional survey was conducted from August to September 2015. Single population proportion formula was used to determine the sample size and multi stage sampling technique was the sampling strategy adopted. A total of 819 children under two years of age were included. Pretest was doneon ten percent of the total sample size. Data were analyzed using Statistical Package for Social Sciences version 20.0 software. Bivariate and multivariate logistic regressions used to analyze the data.