Non-nutritive sucking (NNS) patterns in full-term newborn and preterm infants were studied at term conceptional age. The preterm group showed a distinct NNS pattern with a higher frequency and lower amplitude. In the preterm group, gender differences were observed, the girls having higher frequency and larger amplitude. The full-term infants' NNS patterns were also related to pacifier use during early childhood. Experience, gender, maturity and level of tension are suggested as explanatory factors for differences in NNS patterns.