Exclusive breastfeeding remains critical for child survival, potentially reducing childhood morbidity and mortality. In Uganda, 98% of children are ever breastfed, but exclusive breastfeeding levels remain low. Supporting mothers in breastfeeding exclusively can improve breastfeeding practices. This paper describes experiences of establishing individual peer counselling for exclusive breastfeeding in the Uganda site of the Promoting Infant Health and Nutrition in Sub-Saharan Africa: Safety and Efficacy of Exclusive Breastfeeding Promotion in the Era of HIV trial, and highlights some implications for scaling-up. Twelve women were identified by their communities, one from each of 12 clusters. They were trained for 6 days and followed up for 1 year while they counselled mothers. Their knowledge and attitudes towards exclusive breastfeeding were assessed before and immediately after training, and also 10 months into peer counselling. Observations, field notes and records of interactions with peer counsellors were used to record experiences from this intervention. The communities were receptive to peer counselling and women participated willingly. After training and 10 months' follow-up, their knowledge and attitude to exclusive breastfeeding improved. All were retained in the study, and mothers accepted them in their homes. They checked for mothers several times if they missed them on the first attempt. Husbands and grandmothers played key roles in infant feeding decisions. Involving the communities in selection helped to identify reliable breastfeeding peer counsellors who were acceptable to mothers and were retained in the study. Other key issues to consider for scaling-up such interventions include training and follow up of peer counsellors, which led to improved knowledge and attitudes towards exclusive breastfeeding (ClinicalTrials.gov no: NCT00397150).