To develop into competent communicators infants need to learn to appropriately time their turns in social interaction. Few studies have assessed the actual timing of turn-taking in infant development and debate continues about whether infants actively contribute to the turn-taking. In order to assess whether changes in infants’ vocal turntaking abilities as they get older are really attributable to infants’ improving skills, we analyzed video recordings of 12 mother-infant dyads in free-play interactions longitudinally at 12 and 18 months. Findings indicate that in the first half of the second year of life infants become more skilled in taking turns in vocal exchanges, as evidenced by decreasing onset times of their turns as well as a decrease in the percentage of onsets produced in overlap with their mothers. These changes are not explained by the mothers providing more opportunities to their infants to take their turn. The mean number of utterances produced by the mother did not differ significantly at 12 and 18 months, mothers did not shorten their utterances, nor did they increase the pauses between their consecutive turns. We therefore conclude that infants play an active part in vocal turn-taking exchanges with their mothers and its developmental progress.