Introduction: Infant feeding choices made by mothers in the context of HIV infection depend on a number of factors. In our environment, the relative contribution of some of these factors is not known. Methods: The infant feeding practices of HIV positive mothers seen over a decade (July 2004 and December 2015) at a large HIV treatment centre in Lagos, South-western Nigeria were reviewed. Information on maternal socio-economic characteristics, obstetric, HIV treatment history and infant feeding choices were extracted from the program data base for analysis with SPSS version 20. Results: Exclusive formula feeding (EFF) was the most common feeding practice of the mothers ( 86.4%). However, it decreased from 95.3 % before 2010 to 79.5% after 2010. Exclusive breastfeeding (EBF) was practised by only 9.0% of the mothers. Mixed breastfeeding practice increased from 1.1% pre-2010 to 4.1% post-2010. The provision of free infant formula was found not to influence significantly the EFF or EBF rates but the MBF rate. MBF rate decreased from 3.0% pre-free formula to 1.7% after the introduction of free infant formula. Conclusion: Exclusive formula feeding was the most practised infant feeding method in this study (86.4%). Change in infant feeding guidelines was found to influence the infant feeding choice of HIV positive mothers. Health workers implementing PMTCT programs in our setting should be made aware of the risk of mixed breastfeeding with the new guidelines and educate mothers on its dangers at every contact with the health system.