objective To evaluate a pilot prevention of mother-to-child transmission post-natal programme in Lilongwe, Malawi, through observed retention and infant diarrhoeal rates. methods Free fortified porridge and water hygiene packages were offered to mothers to encourage frequent post-natal visits and to reduce diarrhoeal rates in infants on replacement feeding. Participant retention and infant health outcome were assessed. results Of 474 patients enrolled, 357 (75.3%) completed 3-month follow-up visits. Ninety-nine percent of women reported hygiene package use, and only 17.7% (95% CI 13.8–22.0%) of the infants had diarrhoea at least once over the 3-month period. Being 12 months or younger, confirmed HIV positive, access to tap water, and having a mother with diarrhoea were all associated with increased risk of infant diarrhoea. conclusion The majority of participants adhered to their scheduled visits and retention was favourable, possibly because of the introduction of hygiene and nutrition incentives. The infant diar- rhoeal rate was low, suggesting benefits of regular medical care with hygiene package usage and reliable replacement feeding options. Continuation and expansion of the programme would allow further studies and improve the post-natal care of HIV-exposed infants in Malawi and in other resource-constrained countries.