Paraneoplastic syndromes, which are discussed in this paper, are a heterogeneous group of disorders associated with cancer, but not directly caused by the physical effects of the primary tumor or its metastases. May precede the appearance of the malignant process, occur simultaneously or disclose in the course of cancer. Paraneoplastic syndromes may be caused directly by toxins produced by tumor cells, occur in the course of hypersensitivity reactions, or be the result of release of intracellular antigens. Due to the often similar systemic symptoms it is very important to evaluate the association of rheumatic diseases and cancer. Most paraneoplastic rheumatologic syndroms are difficult distinguishable from idiopathic rheumatologic disorders. The most common paraneoplastic syndromes include rheumatoid arthritis (RA)-like syndrome arthritis, inflammatory myopathies, hypertrophic osteoarthropathy, vasculitis and Raynaud's phenomenon.