Malignancy uncommonly presents with a paraneoplastic syndrome rather than as a direct result of the primary tumour or its metastases. Paraneoplastic syndromes are a heterogeneous group of syndromes that represent the non-metastatic systemic effects of malignant disease. Pathogenesis varies among syndromes but several humoral and immune mediators are implicated. Although some syndromes are rare, they can be very specific for an underlying malignant diagnosis. Recognition of the syndrome, treatment of the malignancy and supportive measures for the paraneoplastic syndrome can improve morbidity and mortality.