BACKGROUND: A small, non-blinded, RCT (randomised controlled trial) had reported that oral antibiotics reduced the incidence of mastitis in lactating women with Staphylococcus aureus (S. aureus)- colonized cracked nipples. We aimed to replicate the study with a more rigorous design and adequate sample size. METHODS: Our intention was to conduct a double-blind placebo-controlled trial to determine if an antibiotic (flucloxacillin) could prevent mastitis in lactating women with S. aureus-colonized cracked nipples. We planned to recruit two groups of 133 women with S. aureus-colonized cracked nipples. RESULTS: We spent over twelve months submitting applications to five hospital ethics committees and seven funding bodies, before commencing the trial. Recruitment to the trial was very slow and only ten women were randomized to the trial after twelve months, and therefore the trial was stopped early. CONCLUSIONS: In retrospect we should have conducted a feasibility study, which would have revealed the low number of women in these Melbourne hospitals (maternity wards and breastfeeding clinics) with damaged nipples. The appropriate use of antibiotics for breastfeeding women with cracked nipples still needs to be tested.