A well-integrated primary health care system helps address the health needs of an ageing population with complex multiple health conditions. In Australia pharmacists provide services to maximise health gains from medication use, although they are not well integrated into primary care. Using the case of Australia, this study investigates why integrating pharmacists in primary care has not been addressed at the national level and also identifies strategies that could promote policy change. Using a unique dataset generated via 33 semi-structured interviews with healthcare leaders and policymakers across relevant disciplines, we undertake a systematic and comprehensive analysis of the policy with the Multiple Stream Framework. This framework examines the policy process with five elements: problem, policy, and political streams; policy entrepreneur; and policy window. The problem stream shows that the primary healthcare system struggles to cope with the increasing healthcare demand and the prevalence of medication-related problems. The policy stream suggests that the consumers would benefit from an integration of pharmacists into primary care to solve these problems; however, policy proposals cannot survive under current circumstances. The political stream reveals the political barriers come from conflicts among interest groups within the profession and the healthcare sector. To advocate their pet policy, policy entrepreneurs should have stronger roles in shaping the “policy idea” to gain its acceptance among the policy community, and to reduce political barriers. Strategies to overcome the barriers include evidence accumulation, role development in light of population needs, and interorganisational collaboration across members of the healthcare network.