Kenya, like the rest of Sub-Saharan Africa and many other developing countries in the world, has made progress in improving newborn health, but did not meet the millennium development goal four for child health. Neonatal morbidity and mortality remains unacceptably high. The objectives of this study were to estimate the burden on neonatal morbidity and determine the socioeconomic and proximate factors responsible for neonatal morbidity in Kenya. A cohort study was carried out at Pumwani maternity hospital, Thika Level 5 hospital and Machakos Level 5 hospital with a sample of 343 stable LBW (2000g) infants. Informed by the concepts of Mosley and Chen (1984) analytical framework, several socioeconomic and proximate factors of neonatal morbidity and mortality were examined. Cross tabulations and multiple logistic regression analyses were done to determine the relationships between these factors and neonatal morbidity. The burden of neonatal morbidity was high, 61.5% (N=343) of the low-birth-weight infants. Micronutrient use, lower birth weight, pregnancy history, infant sex being male, birth complications and source of water as rivers, well and ponds were factors responsible for neonatal morbidity. Stakeholders should develop programs that address these factors to improve newborn health among birth-weight infants.