Recovery of the health sector in post-conflict countries is increasingly initiated through a Basic Package of Health Services (BPHS) approach. The country government and partners, including international donors, typically contract international and local NGOs to deliver the BPHS. Evidence from routine data suggests that a BPHS approach results in rapid increases in service coverage, coordination, equity, and efficiency. However, studies also show progress may then slow down, the cause of which is not immediately obvious from routine data. Qualitative research can provide insight into possible barriers in the implementation process, particularly the role of health workers delivering the BPHS services. The aim of this study was to explore perceptions of health service providers and policy makers on the implementation of the BPHS in post-conflict Liberia, using SRH services as a tracer and Lipsky's work on "street-level bureaucrats" as a theoretical framework. In July-October 2010, 63 interviews were conducted with midwives, officers-in-charge, and supervisors in two counties of Liberia, and with policy makers in Monrovia. The findings suggest health workers had a limited understanding of the BPHS and associated it with low salaries, difficult working conditions, and limited support from policy makers. Health workers responded by sub-optimal delivery of certain services (such as facility-based deliveries), parallel private services, and leaving their posts. These responses risk distorting and undermining the BPHS implementation. There were also clear differences in the perspectives of health workers and policy makers on the BPHS implementation. The findings suggest the need for greater dialogue between policy makers and health workers to improve understanding of the BPHS and recognition of the working conditions in order to help achieve the potential benefits of the BPHS in Liberia.