The relationship between the occupational category of the family and the nutritional status of children was studied. Participants were 340 children up to 11 years of age, living in a small town of a rural area in Paraná, Brazil. The nutritional status of the children, as measured in 1983, was related to the principal occupational categories of the family in the period 1972- 1983. Occupation of the family was categorized as: migrant farmworkers (bóias-frias) throughout the entire period; renters or sharecroppers that were converted to migrant farmworkers; those who never worked as migrant farmworkers; and salaried urban workers that were converted to migrant farmworkers. Other variables included age and sex of the children, condition of birth (home or hospital), number of children up to 11 years of age in the family, birthweight and school enrollment of the children 5 years old or over. The prevalence of wasting was greatest among children belonging to salaried urban workers that were converted to migrant farmworkers. In contrast, this category showed the lowest prevalence of stunting. Compared with migrant farmworkers during the entire period, the odds ratio of wasting in this category was 2.7 with a 95% confidence interval of 1.3-5.7. Wasting and stunting were also independently associated with the number of children (p<0.05). The larger the family, the lower the risk of wasting, whereas for stunting, the larger the family, the higher the risk. These findings suggest an important role for the occupational category in the determination of the nutritional status in children and indicate that wasting and stunting may have differential risk factors.