Under-five mortality remains a major public health challenge in sub-Saharan Africa. Zimbabwe is one of the countries in the region that failed to achieve Millennium Developmental Goal 4 in 2015. The objective of this study was to examine the extent to which maternal health-seeking behaviour prior to and during pregnancy and post-delivery influences the likelihood of under-five mortality among Zimbabwean children. The study was cross-sectional and data were extracted from the 2010/11 Zimbabwe Demographic and Health Survey (ZDHS). The study sample comprised 5155 children who were born five years preceding the 2010/11 ZDHS to a sample of 4128 women of reproductive age (15-49 years). Cox Proportional Hazard regression modelling was used to examine the relationship between maternal health-seeking behaviour and under-five mortality. The results showed that maternal health-seeking behaviour factors are associated with the risk of dying during childhood. Children born to mothers who had ever used contraceptives (HR: 0.38, CI 0.28-0.51) had a lower risk of dying during childhood compared with children born to mothers who had never used any contraceptive method. The risk of under-five mortality among children who had a postnatal check-up within two months after birth (HR: 0.36, CI 0.23-0.56) was lower than that of children who did not receive postnatal care. Small birth size (HR: 1.70, CI 1.20-2.41) and higher birth order (2+) increased the risk of under-five mortality. Good maternal health-seeking behaviour practices at the three critical stages around childbirth have the potential to reduce under-five mortality. Therefore, public health programmes should focus on influencing health-seeking behaviour among women and removing obstacles to effective maternal health-seeking behaviour in Zimbabwe.