OBJECTIVE This study was undertaken in the mid-1990s (1994) to describe the use of tobacco, alcohol, and non-institutionalized drugs among pre-adolescent and adolescent Spanish students. METHODS Information was collected within the framework of a periodic transversal study of life styles among European students, with particular emphasis on health-related habits. In the current study we present the results of the last survey carried out in Spain within the context of this study (1994), which involved a representative sample of Spanish students 11, 13, 15, 17 and 18 years-old (n = 6,711). An anonymous questionnaire was completed by the students in class. The survey sampling uses proportionate stratification and multistage sampling. RESULTS In 1994, 49% of the Spanish students in this age group had tried tobacco. Twenty-four percent were sporadic or regular smokers. There was a large proportion of female smokers than male smokers (27% vs 20%). The overall proportion of smokers increased from 3% at 11 years to 47% at 18 years. One third (33%) of the 18-year-old students smoked daily. Eighty-four percent of the students of this age indicated that they had tried one or more types of alcoholic beverage. Twenty-one percent consumed alcohol regularly (at least once a week). Regular alcohol use was somewhat more common among males (24%) than among females (19%). Forty-six percent of the 18-year-old students consumed alcoholic beverages regularly and 66% had been intoxicated one or more times. Almost one fifth (18%) of the 13-to-18 year-old students indicated that they had tried some type of non-institutionalized drug, although the current rate of consumption was 8%. Cannabis was the drug most frequently tried (18%) and the drug most often consumed at present (8%), followed by cocaine and heroin. More males than females had tried non-institutionalized drugs. CONCLUSIONS Analysis of the data revealed that adolescent tobacco use is increasingly frequent among females. Alcohol use continues to be widespread among Spanish pre-adolescents and adolescents. Alcohol use begins in childhood and becomes consolidated in adolescence. The results suggest, in relation to gender differences in the use of tobacco, alcohol, and non-institutionalized drugs, that there is a strong tendency toward the homogenization of these habits between genders. It is necessary to emphasize the preventive measures of drug dependence among Spanish pre-adolescents and adolescents.