Patients´ experiences of initial periodontal treatment Objective The objective of the present study was to assess the impact of periodontal disease on oral health-related quality of life before and after the initial periodontal treatment (information, instruction, scaling and root planning). Method Patients referred to a specialist clinic in periodontology were invited to participate. A total of 97 (86%) completed the UK oral health-related quality of life questionnaire (OHRQoL-UK) and a check list of questions on their rating and satisfaction with general and oral health before and after initial periodontal treament. Results The patients´ reported an overall improvement in their OHRQoL after the initial periodontal treatment. This was specifically true for the items: general health, well-being and breath odour. They were more satisfied with their general health and their teeth after the treatment. In addition, they rated their oral health higher. Conclusion Initial periodontal treatment improved OHRQoL and patients´ satisfaction with general and oral health, indicating that mechanical infection control is effective assessed by the patients.