Most of the cases of abdominal angiostrongyliasis in Brazil were reported from the southern States of São Paulo, Paraná, Santa Catarina and Rio Grande do Sul (RS). A study in 27 cases from RS revealed a distinct local epidemiology. Peasants were usually affected, either adults or children, from the mountainous areas in the north of the State. There was a seasonal increase in the number of cases, from late spring to autumn, that does not coincide with the rainy season. Besides the most common clinical features of abdominal pain, fever and eosinophilia in the leukogram, painful relapsing episodes were detected in some patients. The abdominal pain could be either localized or diffuse during the rapid evolution to a surgical abdominal condition, with a lethality of 7.4%. The use of a serological test and the greater awareness of physicians working in endemic areas is expected to improve the recognition of uncomplicated and benign courses of the disease. This study confirms the known clinical manifestations of abdominal angiostrongyliasis and demonstrates the diversity of its epidemiology.