This report is part of the European Union cofunded project “Improving Prison Conditions by Strengthening Infectious Disease Monitoring”, led by Harm Reduction International. The project aims to reduce ill treatment of people in detention and improve prison conditions through more comprehensive and standardised monitoring of the human immunodeficiency virus (HIV), hepatitis C virus (HCV), tuberculosis (TB) and harm reduction. The research element of the project has two components. The first includes mapping the current situation relating to HIV, HCV, TB and harm reduction in prisons in seven European countries (Greece, Ireland, Italy, Latvia, Poland, Portugal and Spain), as well as the working practice of human rights-based prison monitoring mechanisms in these countries, with particular reference to HIV, HCV, TB and harm reduction. The second research component is the subject matter of this report, which maps the existing regional and international public health and human rights standards relating to HIV, HCV, TB and harm reduction in prisons, along with the mandate and practice of regional and international human rights-based prison monitoring mechanisms in this regard.