The health sectors in many low- and middle-income countries have been characterized in recent years by extensive private sector activity. This has been complemented by increasing public-private linkages, such as the contracting-out of selected services or facilities, development of new purchasing arrangements, franchising and the introduction of vouchers. Increasingly, however, experience with the private sector has indicated a number of problems with the quality, price and distribution of private health services, and thus led to a growing focus on the role of government in regulation. This paper presents the existing network of regulations governing private activity in the health sectors of Tanzania and Zimbabwe, and their appropriateness in the context of emerging market realities. It draws on a comparative mapping exercise reviewing the complexity of the variables currently being regulated, the level of the health system at which they apply, and the specific instruments being used. Findings indicate that much of the existing regulation occurs through legislation. There is still very much a focus on the 'social' rather than 'economic' aspects of regulation within the health sector. Recent changes have attempted to address aspects of private health provision, but some very key gaps remain. In particular, current regulations in Tanzania and Zimbabwe: (1) focus on individual inputs rather than health system organizations; (2) aim to control entry and quality rather than explicitly quantity, price or distribution; and (3) fail to address the market-level problems of anti-competitive practices and lack of patient rights. This highlights the need for additional measures to promote consumer protection and address the development of new private markets such as for health insurance or laboratory and other ancillary services.