The objective of this study was to see if a coordinated study of both adults and larvae of the calyptrate Diptera would bring out any new relationships within the group. With this objective in mind, larvae of all groups were examined, or descriptions gleaned from the literature, to determine what characters they offered and what groupings they fell into on the basis of the characters found. The present day adult groupings were then re-examined and considered in relation to those offered by the larvae. The resultant classification is based on characters offered by both and has involved a shifting in rank of some groups formerly based only on adult characters.