Introduction: Most studies on nematode-malaria interactions were conducted outside of the Americas. The objective of the present study was thus to study the relation between malaria and nematodes in a cohort of children in an Amazonian village.Methods: Odds ratios for intestinal nematode infections as an explanatory variable to malaria resistant vs. malaria sensitive were computed.Results: Ascaris lumbricoides was significantly more frequent in the 'resistant' malaria group than in the 'sensitive' one.Conclusions: Despite its low statistical power, the present results find that Ascaris was associated with less malaria, as observed by a number of studies.