Background: This retrospective study examined the efficacy of in-home father training on the communicative outcomes of children with autism. The in-home training consisted of two components: (1) expectant waiting; and (2) imitation with animation. Methods: Efficacy of parent training was examined by measuring the ratio of utterances produced by the parents to the utterances produced by the children and the number of verbal imitation by the parents. Outcomes of the children's verbal production were examined by measuring the number of (1) single word utterances; (2) different words produced; and (3) verbal response to questions. Results: Following training there was a decrease in the ratio of parent to child utterances and an increase in (1) the use of imitation by the parents; and (2) the number of single words and different words produced by the children. Discussion: Results of this study suggested that the parents had learned to wait for their children to communicate verbally during communicative interactions and to interact more efficiently with their children by using verbal imitation. Overall, the results of this study support the efficacy of parent training that focuses on promotion of social reciprocity, and have important implications for clinicians and future research.