OBJECTIVE: To investigate prelinguistic vocalization sequences of 1-year-old children with and without cleft lip and palate. DESIGN: Prospective study. PARTICIPANTS: Thirty-eight children born with unilateral cleft lip and palate and 36 control children born without clefts. The cleft children had the lip, soft palate, and posterior part of the hard palate repaired at 4 months of age. The lip was closed ad modum Millard, the nose was corrected according to McComb, and the soft palate was closed with a posteriorly based vomer flap. METHODS: Data were obtained from a clinical visit during which the baby played with the mother. Video recordings were transcribed and analyzed concerning (1) the frequency of occurrence of vocalization sequences, (2) the frequency of occurrence of contoids and vocoids, (3) the contoids' place and manner of articulation, and (4) the percentage of children who entered the canonical babbling stage. RESULTS: No significant differences were observed between the cleft and control groups concerning frequency of occurrence of vocalization sequences, contoids, or vocoids. Structural differences between the groups seem to influence the contoid inventory, with a higher frequency of occurrence of nasal contoids and a smaller frequency of occurrence of alveolar contoids in the cleft group. Canonical babbling was achieved by most children in both groups, and no significant difference was found between the groups. CONCLUSIONS: Early closure of the soft palate seems to have a positive influence on the prelinguistic development of children with cleft palate.