Introduction. The article is based on the concept of parenting myths by Janusz Trempała (2010) and concerns two of them – that the child is the most important in the world, so it should be given the best and that the parent is responsible for ensuring a happy childhood for the child. Aim. The aim of the research was to determine the degree of intensity of maternal beliefs and declared behaviours that result from being guided by parenting myths, as well as to identify socio-demographic variables that are important for beliefs and behaviours. Materials and methods. The author’s own Questionnaire of Selected Parental Myths was used. 1217 mothers (aged 18–55; M = 33; SD = 6) of at least one child aged 1–10 participated in the voluntary, anonymous study. Results. The participating women were moderately guided by educational myths in their beliefs and declared behaviours. Socio-demographic variables had a marginal impact on the results. Conclusion. The popularity of parental myths was related to the specificity of colloquial thinking. The results of the study are discussed in the context of analogous ways of thinking about children of mothers in China, and also the consequences of the decline in fertility in Poland and the increase in the number of one-child families.