The aim was to compare the ethics of historical Indian and New Zealand prospective studies of cervical pre-cancer in terms of: scientific justification, potential harms and benefits to subjects, informed consent procedures, monitoring and stopping, and exploitation. The New Zealand study had poorer scientific justification, greater harm to subjects, absence of informed consent, and greater exploitation. Reasons proposed for on-going criticism of the Indian study are: semantic confusion, lack of consistent detail about informed consent procedures, and failure of a professional obligation to provide on-going medical care. Such criticisms might have been set on a firmer basis, or rejected, if there had been a public judicial inquiry, as happened in New Zealand. Current disagreement about the ethics of randomised trials of cervical screening in India might be resolved through a public inquiry.