Primary health care (PHC) holds great potential to improve maternal, new-born and child health (MNCH) outcomes. Meanwhile, there has been limited documentation of its effect on increasing universal access to maternal, new-born and child health services in sub-Saharan Africa. Also, not adequately known are the most effective interventions to improve the delivery of PHC services in the region. We conducted a systematic review of empirical evidence and interventions at the primary health care level for effective delivery of MNCH care in sub-Saharan Africa. Using terms related to primary health care and MNCH, we searched African Journals Online (AJOL), PubMed/Medline, Popline, ScienceDirect, Google Scholar, WHO Repository (IRIS), Directory of Open Access Journals (DOAJ), Cochrane Library and reference lists for studies published in English between 2000 and 2017. Studies were included in the search if they reported interventions, and strategies implemented to improve quality and access to primary health care for maternal, new-born and child health in sub-Saharan Africa. A total of 25 studies were included in the review. Effective interventions included financial incentives, task-shifting, community-directed engagements, training of providers, mobile health, cost-sharing and supportive supervision among others. The results documented in these studies indicate that effective delivery of primary health care will significantly improve maternal, new-born and child health in sub-Saharan Africa. However, strategies to scale and sustain the successes need to be in place. The protocol was registered on Prospero (Registration number CRD42019126029).