Quality of life, as a science has been steadily gaining importance in both clinical practice as well as research. Despite major progress in the development of validated and clinically-relevant health-related quality of life (HRQOL) measures, we still face many challenges in bridging the gap between what we know and how to apply it in clinical practice: in making the transfer from the mere collection of QOL data to its utilization in improving patient outcome through interventional symptomatic therapy. This manuscript traces the development of QOL as a science to its potential utility in both clinical care and clinical research, as well as an outcomes measure. The emphasis has been placed upon quality of life in oncology with special attention to neuro-oncology.