This study evaluates whether delaying the first bath affects late preterm infants' skin barriers, body temperatures, and comfort. Late preterm infants' skin is drier and has a limited water retention capacity compared to term infants and adults. It is important to determine timing of care for this population with limited competencies. A two-arm, three-center, and single- and evaluator-blind randomized controlled trial was conducted. The study is based on the CONSORT guidelines. The participants were recruited from September 2020 to September 2021. The first baths of participants in the intervention group were postponed until 48hours after birth. Outcomes were measured before bathing and 1, 10, and 30minutes after bathing. There was a statistically significant interaction between the groups and times for transepidermal water loss, body temperature, and comfort. The intervention group had a lower transepidermal water loss value at follow-up than the control group in the forearm and sternum. The control group had lower mean body temperatures and comfort levels. When the first bathing of a late preterm infant is postponed by a minimum of 48hours, it reduces damage to the skin barrier, body temperature is maintained, and the experience is more comfortable. Therefore, the first bath should be delayed for at least 48hours after birth. The study can guide nurses to eliminate the uncertainty of the first bath applied for late preterm infants with a fragile structure in the neonatal intensive care setting and to eliminate the differences between clinics.