Drug usage in early adolescence (age 14) was related to concurrent and preschool personality characteristics for a sample of 54 girls and 51 boys. The personality concomitants and antecedents of drug use differed somewhat as a function of gender and the drug used. At age 14, for both sexes, the use of marijuana was related to ego undercontrol, while the use of harder drugs reflected an absence of ego-resiliency, with undercontrol also a contributing factor. At ages 3/4, subsequent adolescent drug usage in girls related to both undercontrol and lower ego-resiliency. In boys, adolescent drug usage related strongly, during their nursery school years, to undercontrol and with resiliency having no long-term implications. Early family environment related to adolescent drug usage in girls but not in boys. Drug usage in adolescent girls was related to homes earlier identified as unstructured and laissez-faire, where there was little pressure to achieve. Drug usage related to other substance use and, in boys, to IQ decline from age 11 to age 18. Implications of these results for contemporary views regarding adolescent drug usage are discussed.