Postpartum cardiomyopathy (PPCM) is a rare condition that develops near the end of pregnancy or in the months after giving birth, manifesting as heart failure secondary to left ventricular systolic dysfunction. Clinical progression varies considerably, with both end-stage heart failure occurring within days and spontaneous recovery seen. Treatment pathways for heart failure are well established, but the evidence about the safety of medicines passed to infants during breastfeeding is scarce and mainly poor; this often leads to an incorrect decision that a mother should not breastfeed. Given its benefits to both mother and infant, breastfeeding should not routinely be ruled out if the mother is taking heart failure medication but the consequences for the infant need to be considered. An informed risk assessment to minimise potential harm to the infant can be carried out using the evidence that is available along with a consideration of drug properties, adverse effects, paediatric use and pharmacokinetics. In most cases, risks can be managed and infants can be monitored for potential problems. Breastfeeding can be encouraged in women with cardiac dysfunction with PPCM although treatment for the mother takes priority with breastfeeding compatibility being the secondary consideration. International research is continuing to establish efficacy and safety of pharmacotherapy in PPCM.