Objective: The aim of this study was to evaluate the heart and respiration rates, mean arterial pressure, temperature and peripheral oxygen saturation of low-weight preterm newborns, before and after the application of kangaroo mother care. Method: Twenty--two healthy low-weight preterm newborns of both sexes were studied. None of them had neurological, cardiac and/or respiratory deficiencies. Assessments were made after the newborn had been left in an ordinary cot for 30 minutes and after 30 minutes of kangaroo mother care, on three consecutive days. For these evaluations, a heart monitor with a device for non-invasively measuring mean arterial pressure, a sensor for pulse oximetry, a thermometer and a chronometer were utilized. Results: There were no significant changes in mean arterial pressure (p> 0.05) or heart rate (p> 0.05) after applying kangaroo mother care. However, there were significant increases in axillary temperature (p< 0.05) and peripheral oxygen saturation (p< 0.05), and a significant decrease in respiration rate (p< 0.05). Conclusion: Kangaroo mother care promotes improvement in body temperature, increased peripheral oxygen saturation (thus improving tissue oxygenation), and decreased respiration rate (thus providing greater respiratory comfort for the newborns). This suggests that kangaroo mother care contributes towards beneficial alterations in the low-weight newborns' vital signs.