The authors report a case of methotrexate osteopathy as revealed by Tc-99m HDP bone scintigraphy in a patient with rheumatoid arthritis. Methotrexate is used widely in high doses as a chemotherapeutic agent. Lower doses are given in rheumatoid and psoriatric arthritis. Methotrexate affects bone metabolism, resulting in methotrexate osteopathy, characterized by osteoporosis, osseus pain, and even spontaneous (micro)fractures. Radiographic visualization of microfractures is difficult. Tc-99m HDP bone scans have been shown to be very sensitive in the visualization of changes in bone metabolism as a result of methotrexate osteopathy.