Fifteen percent of patients with malignancy are diagnosed endocrinal, hematological, rheumatic or neuromuscular paraneoplastic syndromes. They are more common in males than in females. Rheumatic paraneoplastic syndromes are quite rare. Differences in clinical features, course and outcomes of primary rheumatic disease and paraneoplastic rheumatic syndromes are reviewed. Attention is paid to the need to differentiate paraneoplastic syndromes and real rheumatic disease and the ways to do it. It is generally held that an extensive search for occult malignancy in most rheumatic syndromes is not recommended unless accompanied by specific findings of malignancy.