Given the worldwide epidemiologic transition and the lure of technology aggressively promoted by those profiting from it, policy-makers in developing as well as industrialized countries now frequently face decisions on the introduction of screening into routine health services. Concerns regarding development and equity raise issues that may not arise within the scientific, technical, or individually-focused ethical frameworks used in prior work on screening policy. Screening can divert attention from primary prevention of a society's most important threats to health, especially when primary prevention faces political challenges and screening costs are viewed in isolation from the overall strategy required to make it useful. For secondary prevention of diseases with easily recognizable symptoms, public education promoting timely self-referral to accessible medical services is preferable to "screening" unselected populations. In any country, but perhaps especially in developing countries, screening may waste scarce resources: it could also lead to widened inequities.