Background: There is slower progress on decreasing preterm deaths despite of essential newborn care intervention in Tanzania. About 24% of neonatal deaths in Tanzania occur due to prematurity related complications. However, there are limited studies which explain the knowledge level of postnatal mothers on KMC practice in Tanzania, especially in Central zone. Therefore, the purpose of this study was to determine predictors of knowledge on Kangaroo mother care among postnatal mothers of preterm babies in Central zone, Tanzania.Methods: The study design was an analytical cross sectional involved 363 mothers of preterm babies as participants from three Referral Regional Hospitals in Central zone. Convenience sampling technique was used to get participants in the study where by all postnatal mothers with premature babies who met the inclusion criteria were enrolled until the sample size was attained.Face to face interview using structured questionnaire was used to collect data. Data was analyzed by using SPSS v23. Both univariate and multiple regression analyses were used to determine predictors of knowledge Results: Majority of postnatal mothers 225(62%) had inadequate knowledge towards KMC. After controlling for confounders, predictors of knowledge on KMC were region a postnatal mother was residing [Singida (AOR=1.990 at 95% CI=1.058-3.741, p=0.033)], age of the mother [women aged ≥30 years(AOR=3.913 at 95% CI=1.038-14.75, p=0.044)], level of education of the mother [women who had secondary education and above (AOR=6.309 at 95% CI=2.305-17.26, p<0.001)] and the family type of a postnatal mother living in (nuclear family AOR=0.521 at 95%CI=0.313-0.866,p=0.012).Conclusion: Vast majority of postnatal mothers had inadequate knowledge on KMC practice which threatens the health of preterm babies who are discharged home before full development. Postnatal women who were more likely to have inadequate knowledge were those of young age, with low level of education and living in nuclear families. The study recommends care of preterm babies (including KMC) to be included in the antenatal training package in order to prepare them for the care if they gave birth to a preterm baby.