To evaluate the preventive activities offered to the public by private hospitals in Hong Kong, we obtained information from 11 of the 12 private hospitals about their screening programmes and evaluated them against the standards of the Canadian and United States task forces on preventive health care. We found that not all proven preventive activities are being offered, and many unproven or even possibly harmful actions are provided. The services focus on the application of technology rather than on behaviour change and immunisation, which are the most effective preventive strategies. This focus on testing may give the wrong impression to the public and divert effort from these worthwhile actions. A clear guideline focused on Hong Kong epidemiology and health care would be helpful.