Three female patients, aged 76, 64 and 74 years old, who were treated with low-dose methotrexate due to an inflammatory joint disorder, developed severe pain in a lower extremity. The pain increased on weight bearing and could not be explained by arthritis. Conventional x-ray investigation showed a fracture in the second patient. In the other two patients insufficiency fractures were visualized by MRI and bone scan. Because methotrexate osteopathy was suspected, treatment with methotrexate was stopped. All three patients made a rapid recovery after discontinuation. Methotrexate osteopathy is characterized by pain, osteoporosis and microfractures, and was first reported in children treated with high-dose methotrexate for a malignancy. Similar clinical features are reported in the literature in patients with chronic joint inflammation treated with low-dose methotrexate. The causal relationship between the insufficiency fractures and the use of methotrexate is still under debate. Although the clinical picture fits with methotrexate osteopathy, these patients often also have other risk factors for osteoporotic insufficiency fractures.