A cross-sectional study was performed with 137 mothers and their children aged 0 - 35,9 months attending day-care centers (DCC) of Parobé and Três Coroas, Rio Grande do Sul, Brazil. The study analyzed the duration of breastfeeding among the children according to DCC in the same mothers' working place (internal DCC) or far from mothers' working place (external DCC). The prevalence of breastfeeding at 3, 6 and 12 months was 60%, 26% and 7%, respectively. There was a high statistically significant association between children in internal DCC and breastfeeding over 3 months of life (X2= 18,65; p = 0,00001). Mothers with children in internal DCC breastfed more during their working period then mothers with children in external DCC. The closeness of internal DCC to the working place may give the mothers a sense of serenity and safety. There is also more availability of the mothers to breastfeed during working time, this way maintaining the stimulation to breastmilk production and avoiding the introduction of bottle complements.