BACKGROUND: Although, there are several programs in place in Nigeria to ensure maternal and child health, maternal and neonatal mortality rates remain high with maternal mortality rates being 576/100,000 and neonatal mortality rates at 37/1000 live births (NDHS, 2013). While there are many studies on the utilization of maternal health services such as antenatal care and skilled delivery at birth, studies on postnatal care are limited. Therefore, the aim of this study is to examine the factors associated with the non-utilization of postnatal care among mothers in Nigeria using the Nigeria Demographic and Health Survey (NDHS) 2013. METHODS: For analysis, the postnatal care uptake for 19,418 children born in the 5 years preceding the survey was considered. The dependent variable was a composite variable derived from a list of questions on postnatal care. A multinomial logistic regression model was applied to examine the adjusted and unadjusted determinants of non-utilization of postnatal care. RESULTS: Results from this study showed that 63% of the mothers of the 19,418 children did not utilize postnatal care services in the period examined. About 42% of the study population between 25 and 34 years did not utilize postnatal care and 61% of the women who did not utilize postnatal care had no education. Results from multinomial logistic regression show that antenatal care use, distance, education, place of delivery, region and wealth status are significantly associated with the non-utilization of postnatal care services. CONCLUSIONS: This study revealed the low uptake of postnatal care service in Nigeria. To increase mothers' utilization of postnatal care services and improve maternal and child health in Nigeria, interventions should be targeted at women in remote areas who don't have access to services and developing mobile clinics. In addition, it is crucial that steps should be taken on educating women. This would have a significant influence on their perceptions about the use of postnatal care services in Nigeria.