Background It is crucial to know the extent to which influences lead to policy capture—by which the policy-making process is shifted away from the public interest towards narrow private interests. Using the case study of Spain, our aim was to identify interactions between public administration, civil society and private companies that could influence health policies.

Methods 54 semistructured interviews with key actors related to health policy. The interviews were used to gather information on main policy actors as well as on direct and subtle influences that could modify health policies. The analysis identified and described, from the interviewed persons’ experiences, both the inappropriate influences exerted on the actors and those that they exerted.

Results Inappropriate influences were identified at all levels of administration and policy. They included actions for personal benefits, pressure for blocking health policies and pressure from high levels of government in favour of private corporations. The private sector played a significant role in these strategies through bribery, personal gifts, revolving doors, negative campaigns and by blocking unfavourable political positions or determining the knowledge agenda. The interviewees reported subtle forms of influence (social events, offers of technical support, invitations, etc) that contributed to the intellectual and cultural capture of health officials.

Conclusion The health policy decision-making processes in Spain are subject to influences by stakeholders that determine a degree of policy capture, which is avoidable. The private sector uses different strategies, from subtle influences to outright corruption, taking advantage in many cases of flexible legislation.