In the present investigation wound healing was studied clinically in 8 younger (mean age 33.5 years) and 8 older patients (mean age 48 years), who were surgically treated for the same amount of severe periodontitis. This implies that the patients in the younger age group represented individuals with a higher degree of susceptibility to periodontal disease than the patients in the older age group. After surgery all patients were subjected to a carefully controlled oral hygiene program. Patients were recalled weekly until 8 weeks post surgery and again after 15 weeks for a final examination. At every recall session oral hygiene measurements were carried out and the bleeding tendency of the pockets was determined after probing with a standardized pressure. Bleeding on the basis of mechanical trauma after probing was considered to be a clinical parameter for wound healing in a plaque free environment. Results indicate that the oral hygiene program resulted in equally low plaque scores in both age groups. However, in a period from 5-15 weeks after surgery younger patients showed significantly more bleeding pockets that older patients. Furthermore it was found in both groups that the more loss of attachment there was, the slower the rate of wound healing. It was concluded that the time span for wound healing is longer in patients who are more susceptible to periodontal disease, than in those who are less susceptible.