Although home-based physiotherapy (PT) has an important role in the management of knee osteoarthritis (OA), the optimal frequency of monitoring by the physiotherapist is not known. Ninety-six patients with bilateral Kellgren Lawrence grade 3 OA were divided into two groups. All patients received the same PT program but group 1 was monitored at 1, 2, 3, 6, 12 and 24 weeks, while group 2 was seen at 3 and 24 weeks. At the end of the study, both groups had improved their Hospital for Special Surgery score (P<0.05), and there was no statistically significant difference between the groups. We conclude that the frequency of visits for a home-based exercise program can be decreased without affecting the success of the therapy. (C) 2003 Elsevier Science B.V. All rights reserved.