Previous reports from available trials have dealt with negative long-term sequelae in Hodgkin's disease (HD) survivors. There is, however, a lack of longitudinal data showing the correlation between outcome and various treatment-related variables and the process of re-adaptation into normal life after the end of treatment. In order to investigate the quality of life (QoL) of patients with HD in different dimensions during active treatment and follow-up and to identify longitudinal patterns of QoL dimensions during re-adaptation to normal life within the EORTC Lymphoma Cooperative Group and Groupe D'Etude des Lymphomes de L'Adulte (EORTC/GELA) and the German Hodgkin Study Group (GHSG), QoL assessment strategies were put into use over the last three to five years. Furthermore, the efforts aimed at obtaining cross-cultural comparisons between the participating countries and study groups (EORTC/GELA and GHSG). Within the randomised EORTC/GELA Trial 'H8' for clinical stage I-II HD which started in September 1993, patients receive a QoL questionnaire for completion at each follow-up visit during the first 10 years after the end of active therapy. The corresponding 'HD8' study of the GHSG employs the assessment of QoL during and after active treatment periods. Within both studies, the EORTC QLQ C30 is used for QoL assessment incorporated in the QLQ-S (quality of life questionnaire for survivors), which additionally addresses the aspects of fatigue/malaise, sexuality, specific side effects, and retrospective evaluation of treatment. In total the QLQ-S includes 45 questions on 14 functional, symptom, and fatigue scales, 15 additional single items, and 3 open questions. In addition to the longitudinal QoL assessment, the GHSG carried out cross-sectional QoL trials with all cured surviving patients from the past HD1-6 studies and a matched normal control sample employing the QLQ-S and the life situation questionnaire (LSQ), an instrument covering objective data from 45 domains of life. To date, within the trials H8 and HD8 over 3000 QoL questionnaires from more than 800 patients from ten countries are available for analysis. Replication of the psychometric properties of the scales revealed satisfactory results using factor analyses and reliability testing across languages for the QLQ-S. A feasibility analysis showed generally a good acceptance of the questionnaire by the patients and physicians. QoL assessment within international multicentre trials in HD proved feasible within the two differently organised study groups of EORTC/GELA and GHSG. The use of subjective QoL data (QLQ-S) together with objective data (LSQ) in a combined cross-sectional and longitudinal trial system will give the most comprehensive insight into the problems of the re-integration process into normal life after cure. This information will provide the basis for the development of remedies/help measures and possible modifications of treatment strategies. The current approach will be further developed in close collaboration between both trial groups, and next steps will include translation of the LSQ into other languages and adaptation to various cultural circumstances.