Apnea of prematurity is one of the most common complications in preterm infants hospitalized in neonatal intensive care units. This randomized controlled trial was conducted to evaluate the effect of maternal odor exposure as a developmental care intervention on apnea frequency, physiological parameters, and growth outcomes in preterm infants. Sixty preterm infants were randomly assigned to either a maternal odor intervention group or a routine care control group. The intervention group received maternal odor using a cotton cloth carrying the mother's natural scent for five consecutive days. The primary outcome was the daily number of apnea episodes. Secondary outcomes included oxygen saturation, heart rate, respiratory rate, body temperature, weight, and head circumference.