Pathogenesis of CRMO still remains unknown. Characteristic, but not pathognomonic for this syndrome are clinical course (age, sex, chronic recurrent, intermittent course), radiological findings (metaphyseal lesions), histology (chronic osteomyelitis without colliquation) and microbiological results (lack of pathogen, infectious agents). Favorable, self-limited long-term prognosis of CRMO has been assumed. Antibiotics provide no improvement. Course, severity and recurrency can be influenced positively by antiphlogistic substances, although this has not yet been proved. Whether surgical intervention beyond biopsies might cause improvement on the follow-up is unknown. Our experience (4 cases), and the literature demonstrate great clinical importance that unusual types of osteomyelitis (OM) can be within the differential diagnosis of multifocal osteolytic changes.