Abstract: The presented article will present the issue concerning the knowledge of grandparents about the development of children's speech. This issue seems to be important because grandparents play an important role in the upbringing and shaping of grandchildren. The author used the method of a diagnostic survey in the study. The research tool was a 1, which was completed by one hundred respondents. The obtained results will allow to get to know the grandparents' knowledge ... Material and methods: survey method Results: When analyzing the above answers of the surveyed grandparents, it can be noticed that they have mostly correct general knowledge about the periods of the child's speech development (quantitative aspect). Conclusions: The described state of knowledge of the respondents may contribute to a situation in which grandparents may make inadequate demands on their grandchildren as to their correct pronunciation of sounds or words, which in turn may lead to, for example, conflict situations.