BackgroundPremature newborns admitted to neonatal intensive care units (NICUs) undergo numerous painful interventions during care and treatment. The purpose of this study was to compare the effects of using sucrose and kangaroo mother care by on selected physiological variables and pain resulting from venipuncture in premature infants admitted to NICUs affiliated with Shiraz University of Medical Sciences.MethodsThis clinical trial included premature infants admitted to 2 NICUs. The sample size consisted of 66 neonates, with 22 newborns in each group. Randomization was performed using the block allocation method. Data collection involved a demographic questionnaire, the neonatal infant pain scale, and a pulse oximetry device. Friedman, Kruskal–Wallis, and Dunn’s post hoc tests employed for data analysis, with a significance level of P < 0.05.ResultsThe use of oral sucrose and kangaroo care demonstrated significant differences in breathing rate, heart rate, and average arterial blood oxygen saturation during and after venipuncture (P < 0.05). Oral sucrose was found to be significantly more effective than kangaroo care. Neonates under kangaroo care exhibited more regular heart rates compared to the other group (P < 0.05). The utilization of oral sucrose and kangaroo care had varying effects on the average pain score resulting from venipuncture in premature neonates (P < 0.05).ConclusionsBoth methods proved effective in reducing pain and improving physiological variables. However, due to the superior effectiveness of sucrose administration, it is recommended as a cost-effective and easily implementable method in NICUs.Trial registration: Iranian Registry of Clinical Trials IRCT20191215045749N1. (29/03/2020).