Continuous transcutaneous oxygen monitoring has become standard practice in the management of infants who require supplemental oxygen. Previously described complications of tcPo2 monitoring consist of prolonged intense skin erythema or first degree burns. Two cases of premature infants who developed numerous, hyperpigmented skin craters following prolonged tcPo2 monitoring are reported. Although these lesions appear to be harmless, they have not resolved with time and long-term cosmetic implications are unknown.