Dissertation (MSc Paediatric Nursing)Background: Globally, malnutrition is a public health problem and more than one-third of mortality among children aged below five years is attributable to malnutrition. Therefore a comprehensive nutritional assessment for early diagnosis of malnutrition and care is important. Methods: A cross-sectional study was carried out in a health facility (dispensary) among children aged below five years of age. A total of 302 children were randomly selected from twelve dispensaries in Chamwino district. Standard semi-structured questionnaire was used for data collection. A 24-hour dietary recall was used to determine dietary history from seven food groups. A comprehensive nutritional assessment involving anthropometric, biochemical, clinical and dietary assessment was done. Anthropometric data were entered and analyzed by WHO ANTHRO version 3.2.2 and SPSS computer software version 20. A capillary blood sample was taken to determine hemoglobin concentration. Facility observation checklist was used to assess facility capacity for comprehensive nutritional assessment. Also, nurses‘ knowledge and practice regarding comprehensive nutritional assessment were also assessed. Results: About 38.4% of children aged below five years were stunted, 2.1% were wasted and 9.1% were underweight while 51.7% of them were anemic. Stunting was significantly associated with being unmarried (AOR=2.601; 95% CI=1.215 – 5.570); mother‘s illiteracy (AOR=5.435; 95% CI=1.413 – 20.897) and eating one meal per day (AOR=3.816; 95% CI=1.307 – 11.146). Anemia was significantly associated with food shortage (AOR=2.220; 95% CI=1.306 – 3.775) and lowest dietary diversity (AOR=3.157; 95% CI=1.034 – 9.634). About 41.5% of nurses had moderate knowledge, 39% had good knowledge, while 19.5% had poor knowledge regarding comprehensive nutritional assessment. About 78% had poor practice while 22% had good practice regarding comprehensive nutritional assessment. Additionally, there was a significant scarcity of instruments and tools for nutrition assessment at the facility level. Conclusion: Prevalence of malnutrition especially stunting and subclinical anemia among children aging below five years is still high. Majority of the participated nurses had moderate knowledge and poor practice on comprehensive nutrition assessment. A significant shortage of growth monitoring tools was observed in most of the facilities.