Little research exists that addresses the differences in feeding skills between preterm (PT) infants at term and full-term (FT) infants. The purpose of this study was to quantify and examine the differences in sucking abilities of PT infants when measured at 40 weeks postconceptional age (PCA) and newly born FT infants. The sample consisted of 213 infants who were divided into three groups on the basis of their gestational age at birth (24–29 wk, 30–32 wk, and 38–42 wk). The Kron Nutritive Sucking Apparatus (KNSA) was used to examine the microstructure of sucking and feeding behaviors. There were significant differences among the three groups in several of the sucking variables: number of bursts (p = .005), intersuck interval (p = .0212), sucks per burst (p = .0003), suck width (p < .0001), intersuck width (p < .0001), mean maximum pressure (p < .0001), and intersuck width/interburst width (p = .02). The findings from this study demonstrate the importance of both maturation at birth and experience as factors influencing feeding behaviors.