Purpose: This study was done to investigate the effects of an infant massage on physical growth and stress response in preterm babies. Method: A nonequivalent control group with pre-posttest design was used with 56 preterm babies in the NICU of E medical center at Daejeon. Data were collected from July 2004 to May 2005. The intervention was given for 15 minutes, once a day for 7 days. Physical growth was measured by weight, length, head circumference, and stress response was measured by serum cortisol level. Mean, %, paired-test, t-test with the SPSS/W in 16.0 program were used to analyze the data. Results: After the intervention, physical growth variables (weight, length, head circumference) in experimental group were higher than that of the control group. Also, the serum cortisol level in the experimental group was lower than that of the control group. But none of these results were not statistically significant. Conclusion: The results of this study suggest that a 7-day intervention period may not be long enough to confirm the effects of infant massage on physical growth and stress reaction. Therefore it is suggested that a longer period of infant massage should be tested to determine if it is effective in improving the physical growth and stress reduction in preterm babies.