This study compared reciprocal utterances of six hearing mother-hearing toddler dyads and six hearing mother-deaf toddler dyads. Child participants were matched by language stage based on Brown's stages of morphological development and were aged between 25 and 45 months. Child participants were observed interacting with their mothers during videotaped free play sessions. Language samples containing up to a maximum of 100 child utterances from each dyad were transcribed, coded and analysed. Reciprocal utterance units (RUUs) were compared between the hearing and deaf dyads. Results indicated that significant differences existed between dyads having hearing toddlers and dyads having deaf toddlers with regard to the type and frequency of reciprocal utterance units. Some variations to this general finding are discussed. (Contains 8 tables.)