BACKGROUND The importance of child's play and its assessment for the therapy of deaf children. AIM To analyze the organization of the act of playing between hearing mothers and deaf children, how it can be assessed and its relation with language acquisition. METHOD Analysis of video recordings of six deaf children playing with their mothers in three different moments, with intervals between the recordings of 6 months each. Criteria were established for the analysis of the data. RESULTS All of the children presented a language acquisition delay and a very poor interaction with their mothers. During one year five out of the six mothers modified their way of playing. CONCLUSION Playing might (and should) be an efficient parameter to assess the therapy of deaf children.