The Colombian city of Medellin has faced a severe problem of violence and homicide. The goal of this retrospective, descriptive-analytical study was to assess the magnitude, distribution, most salient characteristics and possible explanations for the problem between 1980 and 2007. Data were obtained from official databases, hospital records and the available literature, and a focus group was set up. There was a dramatic rise in homicides in the city in the time interval studied, with a total of 84,863 documented murders. Ninety-three percent of the victims were male. The 20 to 29 year-old age group was the most affected. Males in this age group, during the worst year of the period (1991), registered an astounding murder rate of 1,709 per 100,000. Even males in the 15 to 19 year age group and the older brackets saw high murder rates. The most common victims were from the lower and lower-middle socioeconomic strata, as has been observed elsewhere in the region. Serious problems were identified in information and in the provision of services. The impact of homicide on the delivery of healthcare services is discussed and a series of tasks for the healthcare sector in the control of this type of violence is proposed.