Preterm neonates hospitalized in the neonatal intensive care unit undergo frequent painful procedures daily, often without pain treatment, with associated long-term adverse effects. Maternal-infant skin-to-skin contact, or kangaroo care (KC), and sweet-tasting solutions such as sucrose are effective strategies to reduce pain during a single procedure; however, evidence of sustained efficacy over repeated procedures is limited. We aimed to determine the relative sustained efficacy of maternal KC, administered alone or in combination with 24% sucrose, to reduce behavioral pain intensity associated with routine neonatal procedures, compared with 24% sucrose alone. Stable preterm infants (n = 242) were randomized to receive KC and water, KC and 24% sucrose, or 24% sucrose before all routine painful procedures throughout their neonatal intensive care unit stay. Pain intensity, determined using the Premature Infant Pain Profile, was measured during 3 medically indicated heel lances distributed across hospitalization. Maternal and neonatal baseline characteristics, Premature Infant Pain Profile scores at 30, 60, or 90 seconds after heel lance, the distribution of infants with pain scores suggesting mild, moderate, or severe pain, Neurobehavioral Assessment of the Preterm Infant scores, and incidence of adverse outcomes were not statistically significantly different between groups. Maternal KC, as a pain-relieving intervention, remained efficacious over time and repeated painful procedures without evidence of any harm or neurological impact. It seemed to be equally effective as 24% oral sucrose, and the combination of maternal KC and sucrose did not seem to provide additional benefit, challenging the existing recommendation of using sucrose as the primary standard of care.