Quantification of quality of life (QOL) related to disease severity is important in patients with atopic dermatitis (AD), because the assessment provides additional information to the traditional objective clinical scoring systems. To document the impact of AD on QOL for both children and adults as well as to quantify the relationship with disease severity, QOL assessments were performed over a 6-month period on 415 patients with AD. A questionnaire derived from the Infants' Dermatitis Quality of Life Index (IDQOL), the Children's Dermatology Life Quality Index (CDLQI) and the Dermatology Life Quality Index (DLQI) was used to determine the QOL for 71 infants, 197 children and 147 adults, respectively. To measure AD severity, both the Rajka & Langeland scoring system and the Scoring of Atopic Dermatitis (SCORAD) index were used. The mean scores were as follows: 7.7 ± 5.5 for IDQOL, 6.6 ± 6.3 for CDLQI, and 10.7 ± 7.9 for DLQI. In conclusion, these QOL scores are correlated with AD severity scores as estimated by the Rajka & Langeland severity score and the SCORAD. The outcome of the QOL instruments in this study demonstrates that atopic dermatitis of both children and adults affects their QOL.