To describe the prevalence, severity and extension of clinical attachment loss (CAL) and to study the predictors in 15- to 19-year-old adolescents from high schools in the Latin America. A cross-sectional, epidemiological study was performed. The sample included 1070 high school adolescents 15-19years of age from Santiago de Chile (Chile), Buenos Aires, Córdoba, Mendoza (Argentina), Montevideo (Uruguay), Quito (Ecuador) and Medellín (Colombia). Calibrated examiners performed full mouth, six sites per tooth clinical examination. There was a response rate of 100%. The prevalence of CAL ≥3mm in ≥1 site was 32.6%, probing pocket depth ≥4mm was 59.3% and bleeding on probing (BoP) ≥25% was 28.6%. The logistic regression analysis adjusted for cities revealed that smoking (OR=1.6), attending public school (OR=2.3) and having a BoP ≥25% (OR=4.2) were positively associated with CAL ≥3mm in ≥ 1 site. Clinical attachment loss was prevalent in Latin America adolescents and it is associated with smoking, attendance public school and BoP.