Conventional radiography, ultrasonography, scintigraphy, computed tomography, and magnetic resonance imaging (MRI) are important diagnostic tools in rheumatology additional to clinical investigation. Radiography provides information both of the juxtaarticular and the abarticular bone. It is relevant in the diagnosis of rheumatoid arthritis, osteoarthritis, spondylarthropathies, and osteoporosis, and for the investigation of other regions like the thorax. Sonography is superior to radiography to delineate soft tissue structures such as effusions, tenosynovitis, tendinitis, paratendinitis, bursitis, and soft-tissue tumors, but also to evaluate bone surfaces. It helps to perform injections and punctures. Furthermore it is a new diagnostic tool for the diagnosis of temporal arteritis, Takayasu's arteritis, and Sjögren's syndrome. Echocardiography, abdominal and pleural sonography are also frequently used. MRI is useful to detect soft tissue lesions and bone lesions. It is helpful to depict synovial membrane, tendon, tendon sheaths, ligaments, cartilage, destructive joint processes, and rupture of synovial cysts. MRI is an established imaging technique in diagnosis of sacroiliitis and cervical arthritis as well as in diagnosis of osteonecrosis. It is an important diagnostic modality for demonstrating early arthritis. MRI is also of interest in diagnosis of neurological disorders of connective tissue diseases or vasculitis in rheumatology. Bone scintigraphy is an established imaging technique in diagnosis of skeletal diseases as well as in diagnosis of tumors. "Hot spots" are seen in locations of high bone turn over. Scintigraphy is also helpful to localize or exclude inflammation.