Background and Aim: Preterm infants' pain is prevalent in the Neonatal Intensive Care Units (NICUs), with numerous invasive procedures happening daily. Repeated and untreated pain have both short- and long-term sequelae. Therefore, the aim of this study was to investigate the effect of auditory versus olfactory stimulation interventions on preterm infants' pain response during venipuncture. Method: A quasi-experimental comparative research design was utilized. A purposive sample of 90 preterm infants was elected from the NICU at Mansoura University Children Hospital. Preterm infants were divided equally into three groups: auditory, olfactory and control groups. A Preterm Infant Assessment Tool, Premature Infant Pain Profile (PIPP), and Neonatal Infant Pain Scale (NIPS) were used for data collection. Results: There was a statistical significant difference between the control, music, and lavender groups concerning their PIPP total mean scores before and after venipuncture and their NIPS total mean scores during venipuncture (p < 0.001). Conclusion: Preterm infants in the music and lavender groups had a considerable reduction in their pain response compared to the control group during venipuncture. Recommendations: Auditory and olfactory stimulation interventions are recommended as simple, safe and low-cost non-pharmacological methods that facilitate positive effects for preterm infants during painful procedures at NICUs.