BACKGROUND: Optimising home oxygen delivery in infants has important logistical and safety implications. This can be aided by having a suitable reference range of normal values for arterial oxygen saturation using pulse oximetry (SpO2). OBJECTIVES: To describe oxygenation profiles in healthy preterm and term infants in relation to gestational and postnatal age, to extend reference values to guide home oxygen therapy. STUDY DESIGN: Prospective monitoring of SpO2 for 4 hours at 3 monthly intervals of 34 term, and 53 preterm healthy infants, took place over a 12-month period using an Ohmeda Biox 3700e pulse oximeter and data logger. RESULTS: Group mean and 5th percentiles were used to construct cumulative frequency curves at each time interval, representing the normal reference range of SpO2 profiles for term and preterm infants over time. CONCLUSIONS: These data may be used to test the benefits in the home or hospital of having a reference range of normal values for cumulative SpO2.