Background: Malnutrition in under five children is prevalent in our country.  It makes them prone to infections and increases child mortality. This can be controlled by identifying and modifying the predisposing factors. Objective: To assess nutritional status and to analyze the influence of various demographic factors on nutritional status of under five children. Methodology: This cross-sectional study was conducted in Shifa Falahi and Community Health center in Islamabad. Children under five years of age were included. Information was collected from mothers on a self-designed questionnaire. Weight and height of children was recorded and classified according to WHO Z score. Data was evaluated on SPSS 20. Univariate analysis was done to determine independent effect of each predictor on outcome. Results: Total of 280 patients were enrolled. 162 (57. 9%) of them were malnourished. Stunting was seen in 24.6% cases, while 26.1% were underweight. Wasting was seen in 19.6% cases. More males were stunted (27.9%) and underweight (27.27%) as compared to females (21.2%) and (24.8%) respectively. Low household income (p value 0.014), poor maternal education (p value 0.018), joint family system (0.002), unboiled drinking water (0.008) and repeated diarrheas (0.02) were found significantly associated with malnutrition. Most of the mothers (>75%) had adequate knowledge of breast feeding, vaccination, seeking medical advice for their babies. Conclusion: All forms of childhood malnutrition are prevalent. Poor socioeconomic status and maternal illiteracy are strong contributors towards malnutrition. Unboiled drinking water and diarrheas are further aggravating the nutritional status of children.