Background The question of when and how to best wean infants born to mothers with HIV requires complex answers. There are clinical guidelines on best approaches but limitations persist when applying them in diverse low-income settings. In such settings, infant-feeding practices are not only dependent on individual women’s choices but are also subject to social and cultural pressures. However, when developing infant-feeding policies little attention has been paid to these pressures, even though they may yield useful empirical knowledge on the various forces that shape the infant-feeding dilemmas confronting women with HIV. This study aimed to a) identify the infant-feeding challenges that women with HIV faced when they were advised to wean their children at an early age of six months and b) explore how the women adhered to their infant-feeding options while facing and managing these challenges. Methods This study was conducted between February 2008 and April 2009 at two public health facilities where services to prevent mother-to-child transmission of HIV were implemented. Repeated in-depth interviews were conducted with 20 HIV-positive women. Two of the 20 women were also chosen for case studies which included home visits. Results Several interdependent factors including the conflicting pressures of sexual morality and the demands of nurturing and motherhood, in conditions of abject poverty, impeded the participating women from following medical advice on infant feeding. If they adhered to the medical advice, the women would encounter difficulty maintaining their ascribed roles as respected wives, mothers and members of the society at large. The necessity of upholding their moral standing through continued breastfeeding, which signified HIV-negative status, put pressure on them to ignore the medical advice. Conclusions The infant-feeding dilemmas for women with HIV are complex. The integration of public health efforts with context-specific socio-cultural understanding is essential. The recent 2010 WHO guidelines offer a possible way of resolving these challenges. They recommend breastfeeding for one year with an adaptation to two years for Malawi. Efforts in the PMTCT programmes to supplement existing support systems, e.g. through the mothers-to-mothers (M2M) programme or consultation with expert mothers may also help women overcome these challenges.