Objective: The objective of this study was to evaluate the effect of repeated painful stimuli on short-term pain response in healthy, term, large for gestational age newborns by measuring the regional cerebral oxygen saturation (rScO(2)), and behavioral and physiological responses. Methods: We compared term large for gestational age infants who received repeated painful stimuli (study group) with term, appropriate for gestational age infants (control group). A pulse oximeter and a near-infrared spectroscopy probe were connected to babies during the study period, and the responses of the babies were recorded by video, from which the crying time and the Neonatal Infant Pain Scale were obtained. The heart rate, peripheral oxygen saturation (SpO(2)), and rScO(2) data were sampled every 1 second and exported to a personal computer via digital output during the study period. The maximum heart rate, the minimum SpO(2), and peak, baseline, and mean rScO(2) measurements following skin puncture were recorded. Data were compared within 1 group and between the 2 groups. Results: After the heel prick, crying time (P<0.001) and Neonatal Infant Pain Scale scores (P=0.024) increased, and SpO(2) levels decreased significantly (P=0.012) in the study group versus the control group. Although mean rScO(2) increased significantly within 1 group (P<0.001), it was not significant between the 2 groups. The percent change in rScO(2) was greater in the study group (5.2 [2.5 to 9.3]) compared with the control group (2.8 [1.1 to 8.2], P=0.037). Conclusion: We showed that rScO(2) values changed significantly within the first few days of life in babies who received more painful stimuli compared with the control group, similar to behavioral and physiological responses.