The authors report the case of a 69-years-old woman with Sjögren's syndrome. After 8 years of disease she developed muscle weakness and the diagnosis of inclusion body myositis was established. This is a rare association. The patient had a good response to the immunosupressive treatment. Similar cases can be found in the literature and there seems to be a subset of inclusion body myositis associated with autoimmune diseases that shows a better response to treatment and a more favourable prognosis.