Despite notable progress reducing global under-five mortality rates, insufficient progress in most sub-Saharan African nations has prevented the achievement of Millennium Development Goal four (MDG#4) to reduce under-five mortality by two-thirds between 1990 and 2015. Country-level assessments of factors underlying why some African countries have not been able to achieve MDG#4 have not been published. Zimbabwe was included in a four-country study examining barriers and facilitators of under-five survival between 2000 and 2013 due to its comparatively slow progress towards MDG#4. A review of national health policy and strategy documents and analysis of qualitative data identified Zimbabwe's critical shortage of health workers and diminished opportunities for professional training and education as an overarching challenge. Moreover, this insufficient health workforce severely limited the availability, quality, and utilization of life-saving health services for pregnant women and children during the study period. The impact of these challenges was most evident in Zimbabwe's persistently high neonatal mortality rate, and was likely compounded by policy gaps failing to authorize midwives to deliver life-saving interventions and to ensure health staff make home post-natal care visits soon after birth. Similarly, the lack of a national policy authorizing lower-level cadres of health workers to provide community-based treatment of pneumonia contributed to low coverage of this effective intervention and high child mortality. Zimbabwe has recently begun to address these challenges through comprehensive policies and strategies targeting improved recruitment and retention of experienced senior providers and by shifting responsibility of basic maternal, neonatal and child health services to lower-level cadres and community health workers that require less training, are geographically broadly distributed, and are more cost-effective, however the impact of these interventions could not be assessed within the scope and timeframe of the current study.