Objective To investigate the nutritional status of individuals from a rural area of Brazil, and associations with helminth infections in an age-stratified sample. Method A total of 1113 individuals aged from 6 months to 83 years from the rural community of Americaninhas in Minas Gerais were investigated. Assessments comprised anthropometric measurements of weight, height and body composition, examining faecal samples for helminth eggs, and peripheral blood assays for albumin, haemoglobin and ferritin concentrations. Results Ten percent of the participants were underweight, 12.8% were overweight and 28.3% of the children and adolescents were stunted. 11.6% had low lean body mass and 28.8% had low fat body mass. Hypoalbuminaemia was seen in 5.5%, anaemia in 12.5% and iron deficiency in 13.1%, although the prevalence of these two indices increased with age. Multivariate analysis showed that, after controlling for age, sex and socio-economic status, stunting was significantly associated with Ascaris lumbricoides infection among children and adolescents, whereas low body mass was significantly associated with hookworm infection among adults and the elderly. Conclusions Helminth infections are associated with undernutrition in endemic populations, with important differences between the effects of hookworm and A. lumbricoides on age-related nutritional status