The primary purpose of this exploratory, cross-sectional study was to determine the degree of agreement between parents' and adolescents' rating of adolescents' asthma-related quality of life (QOL). A secondary aim was to compare the degree of agreement between parent-adolescent dyads in two countries; 15 dyads each were recruited from Kentucky and Iceland. Both adolescent and adult participants completed separate paper surveys at the time of the adolescent's clinic appointment. The QOL instrument used (PedsQL 3.0 Asthma Module) contains the subscales of asthma symptoms, asthma treatment, worry, and communication. Parent-adolescent differences were determined using paired t-tests; associations were assessed with intraclass correlation coefficients (ICCs). Two-sample t-tests investigated between-country differences in parent-child consistency in the assessment of the adolescent's asthma-related QOL. Adolescents rated their QOL higher than their parents did, but not significantly. The ICC of the QOL score for the 30 dyads was 0.39. The degree of agreement was high for asthma symptoms, but low for asthma treatment, worry, and communication. U.S. parents tended to underrate their child's QOL, while parents from Iceland overrated it (p = 0.007). Family-centered interventions may improve parents' understanding of how asthma affects QOL in adolescents, and such interventions may have to be tailored for cultural differences.