Tobacco, alcohol and drug use starts at an early age. It is important to identify risk factors associated with initiation. In 2014, a survey was conducted among students attending first year of secondary schools in Buenos Aires, Cordoba, and Tucuman. A total of 3172 students completed the survey (42% were girls); their mean age was 12.8 years old. Findings showed that 10% had smoked; 32% had consumed alcohol; 17% had a heavy drinking episode in the past month; and 8% had used at least one illegal drug once in their lifetime. A high sensation seeking index was associated with the use of tobacco (odds ratio [OR]: 4.25, 95% confidence interval [CI]: 2.2-8.1), alcohol (OR: 5.56, 95% CI: 3.73-8.31), and marijuana, coca paste or cocaine, (OR: 11.73, 95% CI: 5.81-23.69). Having friends who smoke or drink was associated with tobacco (OR: 12.6, 95% CI: 7.8-20.5) and alcohol use (OR: 5.17, 95% CI: 4.15-6.40). Having permissive parents in terms of media use was associated with tobacco use (OR: 3.7, 95% CI: 2.1-6.5), and perceiving a low parental support and control (OR: 3.02, 95% CI: 1.40-6.52) was associated with marijuana, coca paste and cocaine use.