The present investigation analyses longitudinally the effects of early orthopaedic and/or surgical treatment on maxillary alveolar arch development in 30 children with a complete bilateral cleft lip and palate (BCLP). Palatal arch dimensions were measured on dental casts and their growth velocities during different treatment periods were calculated. Differences in growth velocities between consecutive treatment periods were examined and tested statistically. Furthermore, growth velocities were compared with those of 80 non-cleft children. Before lip closure, growth of the intercanine width of children with a BCLP and non-cleft children was comparable. Only for arch length significantly was less growth observed in BCLP patients in comparison with the control group. After lip closure, intercanine width, arch length and segmental angle diminished. During the intersurgical period, arch form seemed to adapt to a new muscular balance. Immediately after soft palate surgery, growth of the intercanine width and intertuberosity width was restricted. This negative growth was compensated in the postsurgical period, where a catch-up growth of intertuberosity width was even observed.