A significant number of ciliary disease genes have been found to encode proteins that localise to the basal body. By contrast, a large number of basal-body-associated proteins remain to be characterised. Here, we report the identification of a new basal body protein that is required for ciliogenesis in Drosophila. Dilatory (DILA) is a predicted coiled-coil protein homologous to vertebrate AZI1 (also known as CEP131). Mutations in dila specifically exhibit defects in ciliated cells (sensory neurons and sperm). Several features of the neuronal phenotype suggest a defect in intraflagellar transport. In sensory neuron cilia, DILA protein localises to the ciliary base, including the basal body and putative transition zone, and it interacts genetically with the ciliary coiled-coil protein, Uncoordinated. These data implicate DILA in regulating intraflagellar transport at the base of sensory cilia.