The study involved a cross-sectional survey in which respondents were recruited by using snowballing techniques. Interviews were conducted in informal community settings with 100 young drug and alcohol users (45 females) between the ages of 16 and 21 years old. Lifetime prevalence, current frequency, intensity of substance use, and intention to use again were assessed for four target substances (alcohol, cannabis, amphetamines, and ecstasy) together with measures of the perceived functions for their use and peer substance use. Findings show that the lifetime experience of negative effects from using the assessed substances was not found to correlate with current consumption patterns. Statistically significant associations were observed between the reported frequency of taking substances and the perceived social/contextual and/or mood altering functions cited for their consumption. The substance-use function measures, together with the reported extent of peer use, were significant predictors of intentions to use again. If these findings are confirmed in larger studies, this suggests that educational and prevention efforts should acknowledge the positive personal and social functions that various substances provide for youth. The results also call into question the extent to which the experience of negative effects influences future patterns of use. 3 tables and 38 references