Subcutaneous fat necrosis of the newborn is usually self-limited. Rare life-threatening complications include hypercalcemia. The mean time from the development of SCFN lesions to the diagnosis of hypercalcemia is 24 days, and it resolves within 6 weeks after diagnosis. The hypercalcemia is mostly moderate (<3 mmol/L) and without clinical symptoms. However, kidney calcium deposits occur. High blood calcium levels can be detected up to 3 months after diagnosis. Therefore, the authors recommend systematic monitoring of calcium levels for 2 to 3 months in newborns with SCFN. The pathogenesis of hypercalcemia may include extrarenal production of 1,25-dihydroxyvitamin D3 by macrophages stimulating intestinal calcium uptake,2,3 elevated prostaglandin E stimulating bone resorption,6 and calcium released from the resolving subcutaneous plaque.3 Other complications include dyslipidemia, thrombocytopenia, hypoglycemia, and, rarely, progression to subcutaneous atrophy.