The aims of dental hygiene treatment are health promotion and disease prevention. For a successful treatment it is necessary with patients´ adherence. It is consequently important to assess patients´ perspective of the treatment and its outcome. The research within dental hygiene and dentistry has traditionally focused on clinical outcomes neglecting patients´ experiences. Within medicine and nursing the concept of health-related quality of life (HRQoL) are increasingly incorporated as an outcome measure in studies. In dentistry and dental hygiene the concept oral health-related quality of life (OHRQoL) has been introduced and a growing number of studies have been conducted. This presentation will focus on the concepts HRQoL and OHRQoL. Different instruments to assess the concepts will be discussed and new research in the area will be presented.