Acute rehabilitation refers to the multidisciplinary rehabilitative treatment of patients in continuing need of integrated acute and rehabilitative longterm care. As a result of the advances in acute rheumatology and improved emergency services, an increasing number of patients survive episodes of severe disease and complications of immunosuppressive therapy. These patients require not only treatment of their acute medical problems but also specialized multidisciplinary acute rehabilitation starting as early as possible during their hospital stay. We describe 4 typical cases from the major fields of rheumatology. (1) Acute rehabilitation of a 63-year-old woman with rheumatoid arthritis after replacement of both preexisting knee endoprostheses in one session and removal of the left hip endoprosthesis due to infection and sepsis. (2) Rehabilitation of a 29-year-old man with a 7-year history of ankylosing spondylitis who lived in an adjustable easy chair for 2 years due to severe pain prior to admission. (3) A 61-year-old woman with active refractory Wegener's granulomatosis who developed respiratory insufficiency due to aspergillus and pseudomonas pneumonia. (4) The acute rehabilitation of a 21-year-old woman with systemic lupus erythematosus and a history of 14 laparotomies due to severe acute pancreatitis and multiple gut perforations. Acute rehabilitation was complicated by a large defect of the abdominal wall and significant critical illness polyneuropathy. Our report points out differences between acute, postacute, and longterm rehabilitation, describes the mobilization of patients in acute rheumatology units, and defines specific problems encountered in acute hospital-based rehabilitation of rheumatological patients.