Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Schistosomiasis or bilharzia is a parasitic disease found in tropical countries. Most infections are subclinical but may progress to chronic form characterized most frequently by the presence of liver involvement and portal hypertension. We report a patient that presented chronic polyarthritis with positive rheumatoid factor. During investigation, increased liver enzymes, negative hepatitis serologies and signs of portal hypertension on an ultrasound examination raised suspicion of S. mansoni infection. We will discuss pathophysiology and clinical manifestations of S. mansoni infection with special attention to articular involvement.33513411343Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [2009/16785-1, 2008/02917-0, 2009/06049-6]CNPq [300447/2009-4]