Quality of life (QOL) has become a widely used outcome parameter in the evaluation of treatment modalities in clinical oncology research. By now, many of the practical problems associated with measuring QOL in clinical practice can be overcome by the use of computer-based assessment methods. QOL assessment in oncology is dominated by two measurement systems, the FACT scales and the EORTC QLQ-C30 with its modules. The amount of human resources required to implement routine data collection has been reduced significantly by advanced computer technology allowing data collection in busy clinical practice. Monitoring of QOL can contribute to oncologic care by facilitating detection of physical and psychological problems and tracking the course of disease and treatment over time. Furthermore, the integration of screening for psychosocial problems into QOL monitoring contributes to the identification of patients who are in need of psychooncologic interventions. Computer-based QOL monitoring does not replace the direct physician-patient communication but enables to identify specific impairments and symptoms including psychological problems. Beyond clinical practice, QOL data can be used for research purposes and may help health care planners to determine those patient services that should be maintained or ones that should be developed.