An increase in the use of cocaine and crack in several parts of Europe has raised the question whether this trend is similar to that in the USA in the 1980s. However, research in the field of cocaine use in Europe has been only sporadic. Therefore, a European multi-centre and multi-modal project was designed to study specific aspects of cocaine and crack use in Europe, in order to develop guidelines for public health strategies. Data on prevalence rates were analysed for the general population and for specific subgroups. Despite large differences between countries in the prevalence of cocaine use in the general population, most countries show an increase in the last few years. The highest rate, with a lifetime prevalence of 5.2 per cent, was found for the United Kingdom, although with a plateau effect around the year 2000. With regard to specific subgroups, three groups seem to show a higher prevalence than the general population: (1) youth, especially in the party scene; (2) socially marginalised groups, such as the homeless and prostitutes or those found in open drug scenes; (3) opiate-dependent patients in maintenance treatment who additionally use cocaine. Specific strategies need to be developed to address problematic cocaine use in these subgroups.