Comparative prison health is marked by three paradoxes: while problems are similar, responses vary a great deal; the image of the prison population as young, male and healthy is contrasted against the excessive use of health services; prison health service is criticised if standards are worse, but also if they seem better than outside prison. This text highlights current controversies in prison health, pointing to some of the main health problems in prison and outlining the pattern of responses in individual European countries, and also at the European and global level. Because many prison health issues are controversial, and these controversies are reflected in law, examples are used instead of a comparative overview. The interplay between three sources of guidance, namely law enforcement, health and human rights, has marked the recent process of change from prison into prisoners' health law, which has been based on the acceptance of equivalence as the ultimate goal. This has made a substantial change in the very approach to regulating prison health - rather than part of the penitentiary, prison health is increasingly seen as part of the health system. The acceptance of equivalence has had profound consequences for both prisoners and health professionals working in prison. The rights of patients-prisoners are not yet fully recognized, nor is their access to health care guaranteed similarly to patients at liberty, but the process of effective recognition is progressing rapidly. The health personnel in many countries retains its dual - and often conflicting - role of prison and prisoners' health service. Legislative changes have, in some countries, separated health from penitentiary law, and subsumed prison health under the general health law. Even where this has not been accomplished, the utilization of professional and ethical standards, and of human rights procedures, have contributed to their enhanced professional independence.