PURPOSE: Accurate management of infant temperature requires appropriate placement of temperature monitoring probes. Currently, there is a lack of consensus regarding placement of skin temperature probes and the effect on temperature monitoring of the infant's lying on the probe. The objective of this study was to compare abdomen and back skin temperatures when infants were positioned supine and prone. DESIGN: A quasi-experimental design was used to randomize infants to prone or supine position. Infant back, abdomen, and axillary temperatures were measured at one-minute intervals with small disposable thermocouples over a one-hour period. SAMPLE: Twenty-three infants, weight 820-2,400 gm, gestational age 27-37 weeks, postnatal age three to ten days. MAIN OUTCOME VARIABLE: Gradient between abdomen and back temperature. RESULTS: Both mean abdomen and mean back temperatures differed significantly by position (t-test, p = .003 and .028, respectively). Weight and postnatal age did not have an effect on the mean difference between abdomen and back temperature. Results indicate that probe placement and infant positioning are important factors altering measurement of skin temperature.