Abstract:Of the estimated 10.2 million people incarcerated worldwide on any given day in 2014, it is estimated that 3.8% have HIV (389,000 living with HIV), 15.1% have HCV (1,546,500), 4.8% have chronic HBV (491,500), and 2.8% have active tuberculosis (286,000). The prevalence of HIV, hepatitis B virus, hepatitis C virus, and tuberculosis are higher in prisons than in the general population in most countries worldwide, mainly because of the criminalization of drug use and the detention of people who use drugs. Another important risk factor is sexual behavior, where MSM represent major risk for transmission of infectious diseases. Overcrowding and poor infrastructure are responsible for parasitic infections. Improving conditions in prisons, finding alternatives to detention and mostly available HAART and preventive programs for HIV, HCV and tuberculosis, could be the options how to lower the numbers of infected people.