The aim of this study was to assess the knowledge on mother-to-child-transmission (MTCT) of HIV, describe what advice pregnant women receive concerning these issues and investigate breastfeeding practises and infant feeding patterns in general. During six weeks in 2004, a structured interview was carried out among 41 women in Moshi, Tanzania. 11 women were HIV-infected. 90% of the women were aware of MTCT, and 80% knew of the role breastfeeding has in vertical transmission. There was a strong correlation between a higher level of knowledge and increasing age and marital status. When it comes to advice on infant feeding, 100% of the HIV-positive and about half of the non-infected women had received guidance on the topic. The vast majority of women who had been informed on infant feeding, were encouraged to breastfeed exclusively, regardless of their HIV-status. While 92,7% of the women did breastfeed, only 22% performed exclusive breastfeeding. HIV-positive mothers and mothers of young babies were more likely to breastfeed exclusively. The HIV-infected women stated that fear of revealing their HIV-status was a main reason to why they continued to breastfeed. This is also an important explanation to why exclusive breastfeeding is considered more acceptable and feasible than replacement feeding. 75% of the HIV-positive women did partly succeed in following the recommendations set by WHO concerning infant feeding. This means that they either breastfed exclusively for the first few months or that they abstained from breastfeeding and provided milk substitutes and weaning food for their children in stead.