Objective <p>To evaluate the effect of breast milk odor on feeding performance during the first oral feeding of preterm infants.</p> Study design <p>A randomized controlled trial was conducted with 60 preterm infants (26–34 weeks’ gestation) in a level-3 NICU in Istanbul. All infants received non-nutritive sucking with a pacifier as standard care. The experimental group (<i>n</i> = 29) additionally received olfactory stimulation with breast milk odor for 1 hour before the first oral feeding, while the control group (<i>n</i> = 31) received pacifier only. Feeding performance was compared between groups. The study was registered at ClinicalTrials.gov (NCT06563973).</p> Results <p>Feeding duration was shorter in the experimental group than in controls (9.17 ± 1.95 vs. 10.90 ± 2.83 min), and feeding rate was higher (3.84 ± 0.98 vs. 3.22 ± 1.09 mL/min). Experimental group infants also had significantly higher alertness and energy scores on the Early Feeding Skills Assessment.</p> Conclusion <p>Exposure to breast milk odor before the first oral feeding may enhance feeding performance in preterm infants.</p> Clinical trial registration <p>The trial has been registered on <a href="http://www.clinicaltrials.gov">www.clinicaltrials.gov</a>, ID: NCT06563973. (<a href="https://clinicaltrials.gov/study/NCT06563973">https://clinicaltrials.gov/study/NCT06563973</a>). Patient enrollment began prior to trial registration due to the urgency of recruiting within a limited study period and delays in obtaining access to the trial registration platform. The study protocol was finalized and approved by the institutional ethics committee before enrollment, and no changes were made to the protocol after registration.</p>