Relationships within the family can influence a child's perceptions about the school, kindergarten and school teachers, how he behaves in different environments, and his school adjustment. In the family environment, parenting is a process, through which a child can shape his beliefs, values, interest and motivation. Recently, fathers are involved in upbringing more than ever. Thus it is essential to understand the nature of their contribution to parenting. In my master's thesis, we were interested in the mothers' and fathers' parenting behavior in relation to their children's school adjustment (social adjustment and academic achievements). The aim is to determine if the harmony of parenting practices of mothers and fathers is related to their children's school adjustment. The study participants were 234 elementary school students (entered in the 6th and 7th grade in the school year 2019/2020) and 18 teachers. The data was collected using Parenting Behaviors and Dimensions Questionnaire – PBDQ, School Social Behavior Scales 2 – SSBS2 and each child's average student grade in the last school year. Perceived positive parenting behaviors (democratic discipline, autonomy support and emotional warmth) in mothers and fathers are connected to their child's social adjustment and academic achievement. Within the negative parenting behaviors, only the mother's punitive discipline is connected to the child's social adjustment and academic achievement. Harmony of mother's and father's parenting behaviors is positively connected to their child's social adjustment and academic achievement. The exception was the harmony of the mother's and father's punitive discipline, which is not connected to a child's school adjustment. My master's thesis builds upon the awareness-raising about the importance of parenting behaviors related to children's outcomes in the school environment.