Introduction: Drug addiction as a bio - psycho - social life problem impact all aspects of life including quality of life, in this way adolescents and young people are more vulnerable than other groups against this dangerous phenomenon. This study aim was to determine the quality of life and relation with background characteristics and family relationships in adolescents and young people in initial of Methadone Maintenance Therapy in Isfahan city.

Method: This study was a cross sectional study that was conducted in a convenience sampling among137 adolescents and young people ages 12-25 at the beginning of entering to the addiction treatment centers in Isfahan city.

Findings: Among the eight domains of quality of life, social functioning mean lower quality of life was reported (42.79 percent). Demographic characteristics, it was found that the quality of life with age, employment status and income were not statistically significant, while the age at the onset of addiction, marital status, and is statistically significant. Quality of life had a positive correlation with family relationships and family problem.

Discussion: This study showed that drug-dependent persons had the lower quality of life, especially in social activities. Due to study results, pay attention to family problems and family relationships of adolescents and young people and its relation to quality of life are important. Therefore, in order to treat and reduce the recurrence of addiction in adolescents and young people, according to the quality of life, especially social and family relationships are important.