BACKGROUND Transplanted women are increasingly expressing their desire to breast-feed. Due to the unknown effects that might occur in newborns of everolimus-treated mothers, it is now recommended to inhibit lactation. This report discusses the assessment of everolimus levels in maternal, umbilical, and neonatal blood, and colostrum of a kidney transplant mother. CASE REPORT A 28-year-old white primipara after second kidney transplant, treated with everolimus, conceived unintentionally. Due to the high risk of recurrence of primary disease, the immunosuppressive treatment remained unchanged. At 37 weeks of gestation, due to mild preeclampsia, the woman was qualified for induction of labor and vaginally delivered a healthy infant. The highest concentration of everolimus in the colostrum was observed 4 h after drug administration and was 0.066 ng/ml. The estimated maximal dose of everolimus in colostrum was 0.38% of the mother's dose. CONCLUSIONS Breast-feeding in transplanted women treated with everolimus seems possible, particularly in mothers who are willing to breast-feed, especially in the first days after labor, when levels of immunoglobulins in colostrum are high and the concentrations of everolimus are low.