Adolescents' consumption of tranquilizers, sedatives, and sleeping pills (TSSp) has increased during the last few decades, and TSSp are currently among the substances with the lowest age-of-onset. We characterized current-use patterns of TSSp consumers by age when first taken. This study used individualized secondary data retrieved from the 2016 Spanish State Survey on Drug Use in Secondary Education (16-18-year-olds), and included all subjects who reported having taken TSSp at any point, but excluded those who had started during the previous year (n = 1502). Logistic regression models were used to obtain adjusted odds ratios (aOR) for associations between early TSSp consumption (<14 years) and current TSSp use patterns, adjusted for sociodemographic factors. About 17.9% of respondents had taken TSSp (average age-of-onset = 13.7) and 45% of these without a prescription. TSSp consumption at <14 years was higher for males and nonrepeaters. Having begun to use TSSp < 14 years was associated with both higher probability of consumption in the last month (aOR = 1.41; 95%CI:1.12-1.77) and daily/almost daily consumption in the last month (aOR = 1.56; 95CI%:1.16-2.08). The results of this study show there is a high proportion of 16 to 18 TSSp student consumers - both prescribed and nonprescribed; it also establishes that early onset-of-use is associated with higher levels of intensive use later on.