To determine the attitudes of South African general practitioners (GPs) to national health insurance (NHI), social health insurance (SHI) and other related health system reforms.A national survey using postal questionnaires and telephonic follow-up of non-responders.GPs throughout South Africa.Four hundred and forty-three GPs were randomly selected from a national sampling frame of 6,781 GPs.Acceptance of NHI and GP preferences with regard to financing, provision, benefits, coverage and the role of GPs.A response rate of 82.1% was achieved. Sixty-two per cent of GPs approved of the introduction of some form of social or NHI in South Africa, while 24.1% disapproved. Approval rose to 81.6% if GPs were to maintain their independent status, e.g. own premises and working hours, to 75% if additional private top-up insurance was allowed, and to 79.9% if payment was by fee-for-service. Seventy per cent of GPs in the study stated that they had the capacity to treat more patients. The most important reason given for approving of NHI was to make health care more equitable and accessible to the majority of South Africans. A high proportion of GPs approved of increasing the level of interaction between GPs and district health authorities.Most GPs approved of some form of social or NHI system, provided that the system did not significantly threaten their professional autonomy or economic and financial situation.