This study evaluated the profi le of public and private high school students (N = 254, M age = 15.1, SD = 1.3) in the city of São Paulo in relation to their Internet use patterns and quality of life. We used the Internet Addiction Test and the Pediatric Quality of Life Inventory. About 70% of the students had moderate Internet addiction. Those students from public school showed higher scores of Internet addiction (p < 0.001) than students from private schools. Regarding the quality of life, those from private school showed better scores regarding academic performance (p < 0.01) and worse scores in social aspect (p < 0.05). The data showed a strong association between Internet addiction and poor levels of quality of life, as observed in studies from other countries. Keywords