To measure the variation in Brain-Derived Neurotrophic Factor (BDNF), Thiobarbituric Acid Reactive Substances (TBARS) and interleukin (IL) levels in crack-cocaine dependent adolescents after 21days of abstinence, comparing to levels found in a group of healthy controls. Cross-sectional nested on a short follow-up study. Two inpatient treatment units for adolescents, and a low-income neighborhood. 90 adolescents, of both genders, with diagnosis of crack cocaine dependence, and 81 healthy adolescents. Serum levels of IL-6, IL-10, TBARS and BDNF were assessed on admission and discharge. Drug addiction severity was assessed by the Addiction Severity Index - Teen Version (T-ASI) and Cocaine Craving Questionnaire - Brief version (CCQ-b). Psychiatric comorbidities were assessed by the Schedule for Affective Disorders and Schizophrenia for School-Age Children - Present and Lifetime Version (K-SADS-PL). Generalized Estimating Equations (GEE) were used to estimate the IL-6, IL-10, TBARS and BDNF levels, adjusted for confounders. Hedges' g was used to estimate effect size. TBARS (p=0.005, d=0.04), IL-6 (p=0.027, d=0.40) and IL-10 (p=0.025, d=0.41) were elevated and BDNF (p<0.001, d=0.62) was reduced (p<0.001), in patients, in comparison to controls, at admission time. Variation in those levels between admission and discharge were not significant. Crack-cocaine use seems to be associated with inflammatory and oxidative imbalances in adolescents.