PIP: Preliminary data on household structures of proletarian and semiproletarian workers in 3 municipios of the state of Puebla, Mexico, are presented. This work is part of a larger study of the 5 municipios with the highest proportion of industrial workers in the state of Puebla. Among the 3 municipios in the present study, Puebla contained 48.4% of the state's industrial workers, Tehuacan 6.9%, and Cholula 3.9%. A structured questionnaire was used during interviews with 27 male and 25 female factory workers in Puebla, 24 male and 15 female workers in Cholula, and 25 male and 20 female factory workers in Tehuacan. 16% of households of industrial workers in Puebla and Cholula supplemented their wage income with agricultural work, compared to 27% in Tehuacan. 10 of the workers, all women, were under 20 years old. 73% of women workers were under 30 years old, compared to 34% of the male workers. Women workers virtually disappeared after 40 years. Less educated women tend to enter the labor force at early ages and use their incomes to aid the parental budget. The tendency is reinforced by the preference of factories for a very young female labor force that also stops working a young age due to marriage. Women supported households alone in 8 cases and with the aid of other women in 4 cases. 52 households depended on the income of 1 man and another 17 on the income of more than 1 man. 48 of the women but only 7 of the men belonged to households in which both men and women were economically active. Households supported by just 1 man tended to be quite large. The data suggest a postponement of the age at 1st pregnancy among female workers.