The practice of exclusive breastfeeding prevents malnutrition, mortality and morbidity. This has been demonstrated in the developed countries. However in Kenya 1.5 million children are born each year and only 500,000 million of them are exclusively breastfed. About one million children are exposed to unnecessary risk of malnutrition and increased morbidity. There is limited information on exclusive breastfeeding especially on practices that promote exclusive breastfeeding. This study therefore, assessed the breastfeeding practices of 167 mothers with children aged between 0-6 months in Kiamabundu location of Kisii County. The objectives were; to determine the practice of exclusive breastfeeding and influence of cultural practices, maternal practices, psychological practices and physiological practices among mothers with children aged between 0-6 months in Kiamabundu location of Kisii County. The purposive sampling method was used in the study. The quantitative data were collected using a structured questionnaire and analysis was done using inferential statistics by the statistical package for social sciences (SPSS version 24.0) software. Chi-square was used to test for the relationship between exclusive breastfeeding and other variables namely maternal, physiological, psychological and cultural practices among mothers with children aged between 0-6 months in Kiamabundu location of Kisii County. Any P-value below or equivalent to 0.05 was considered to be statistically significant. The study showed that only 32.9% were practicing exclusive breastfeeding. The study further showed that opposition to expression of breast milk as a cultural practice has influence on exclusive breastfeeding (P value = 0.04). Additionally knowledge and prolonged time before introduction of breast milk as maternal and physiological practices respectively had influence on exclusive breastfeeding (P value = 0.05). Other practices were not statistically significant (P value > 0.05). In conclusion, cultural, maternal and physiological practices have influence on exclusive breastfeeding. The study recommends more education on exclusive breast feeding, incentives to be introduced for mothers who attend clinic up to 4 times during pregnancy. More studies should be carried out to determine why mothers delay introduction of the child to the breast after delivery.