To assess the health-related quality of life of Pakistani adolescents with type 1 diabetes mellitus and their parents. This cross-sectional study of adolescents with T1DM and their parents was conducted at Baqai Institute of Diabetology and Endocrinology, a tertiary care hospital, Karachi Pakistan from April 2017 to September 2018. Diabetes Quality of Life for Youths (DQOLY) questionnaire (assess possible problems in six dimensions of impact) and WHO QOL-BREF instrument was used to assess quality of life of adolescents with type 1 diabetes and their parents respectively. The data was entered and analyzed using IBM Statistical Package for Social Sciences version 20. Adolescents with T1DM had adverse impact on their quality of life (QOL); overall QOL score was found 20.76 ± 0.83, the maximally reported adverse impact was related to symptoms of diabetes 24.35 ± 1.92 and impact of treatment 24.59 ± 2.12. Females had more adverse impact on QOL score, i.e. 22.49 ± 1.2 (p value = 0.015). Adverse effect on QOL score is strongly correlated with increasing age (p value = 0.006). Overall QOL score of parents/care takers was 56.3 ± 0.98. The worst overall QOL score was noted to be of care takers 53.75 ± 3.4 followed by mothers 54.52 ± 1.25 and fathers 60.56 ± 1.61 respectively (p value = 0.015); the environment domain was associated with statistically significance adverse impact on QOL of mothers (p value = 0.008). It is imperative for health care professionals to be aware of the effect of diabetes on QOL as timely screening is important for better health care outcomes.