The purpose of the present study was to investigate the communicative functions of mutual touch during mother-infant interactions and their relation with infants’ affect and the quality of the mother-infant relationship. The two normal periods of the Still-Face procedure were examined for mothers and their 5½-month-old full-term (n=40) and very low-birthweight/preterm (VLBW/preterm; n=40) infants. The Functions of Mother-Infant Mutual Touch Scale was used to code the function of each mutual touch. Results indicated that full-term infant-mother dyads spent significantly more time engaged in playful and regulatory mutual touch compared to VLBW/preterm infant-mother dyads who spent significantly more time engaged in attention-centered, unbalanced, and guided mutual touch. Infant smiling was found to significantly co-occur with playful mutual touch for both the full-term and VLBW/preterm infants, while fretting co-occurred with unbalanced mutual touch for VLBW/preterm infants. Higher levels of maternal sensitivity and regulatory mutual touch were associated for full-term dyads, while lower levels of maternal sensitivity were associated with unbalanced mutual touch for VLBW/preterm dyads. Results from this study enable a more comprehensive understanding of the functions of mutual touching, and suggest key differences in which mutual touching behaviours are organized with infants’ affect and relationship dimensions between mothers and their infants.