Purpose Supporting countries to improve access to medicines is a core function of the World Health Organization (WHO), but country experiences are rarely documented. Yet, with the changing health landscape and a multiplicity of partners on the scene, WHO's special contribution to a country may not be obvious. We highlight the role of WHO in supporting the Government of Kenya to strengthen pharmaceutical systems over the past five years, to share lessons learnt and identify best practices; and also to provide a critical analysis and WHO policy perspectives on Kenya's pharmaceutical sector. Key contributions WHO’s intensified support to Kenya's pharmaceutical sector dates back to the early 1990s. Support has focused upstream, targeting critical processes, policy gaps and key institutions. Standardized tools and methods were applied to identify gaps and strategies, multi-stakeholder approaches were facilitated, and WHO expertise has been channelled from all levels. As a result, policies and strategies for improving access to essential medicines have been elaborated; key national institutions have been restructured and two quality control laboratories have attained WHO prequalification status. The country’s pharmaceutical situation is better understood and this knowledge is guiding policy implementation. This report compares Kenya's pharmaceutical situation in 2003 and 2008 - that is, before and after major interventions were made to address the shortcomings in pharmaceutical policies and systems. Capacity was enhanced for medicines regulation, including quality assurance and control of counterfeits; human resources; medicines supply; and appropriate use of medicines. Findings WHO’s unique technical resources have strengthened key pillars for improving and monitoring access to essential medicines in Kenya. WHO optimizes its resources when they are channelled to facilitate Government-led, multi-stakeholder approaches and to maintain a focus on public health priorities. While many partners have recently entered the health sector and are providing various forms of support, WHO's normative and technical guidance on pharmaceutical matters is highly valued by the Government and partners. Main recommendations Addressing pharmaceutical issues tends to be complex as many interested parties are involved. Given the critical importance of pharmaceuticals to public health, pharmaceutical issues cannot be left to market forces alone. Strong Government leadership and oversight are required to regulate the market, and to ensure equity in access to essential medicines. Government's role should not be confined to managing pharmaceutical requirements for health-care services, but to guiding all aspects of the pharmaceutical sector, including regulation, innovation, manufacturing and trade matters. In addition, because pharmaceutical issues transcend national borders, there is a need to explore innovative approaches in addressing cross-border regulatory regulatory standards, and also for controlling trade in medicines. Above all, however, the challenges identified in this review will require continued technical support from WHO to overcome them.