In order to identify differences in the neuropsychological mechanisms of the development of orthographic competence in boys and girls, a correlation analysis of data obtained through the use of a complex of neuropsychological tests and data from a survey of written language of students was conducted. The sample of a study was 150 people. The research results allow us to conclude about the different conditionality of the success of mastering Russian orthography in groups of boys and girls. In both groups the linkages between the level of orthographic competence and the success of the tasks of the “Kohs Block Design Test” was revealed. Additionally, correlations of the success of mastering orthographic skills and the state of mechanical verbal memory, as well as the development of thinking (excluding superfluous) were revealed in the girls. In the boys group, correlations of the indicator of the number of orthographic errors with indicators of the formation of dynamic praxis, reproduction of rhythmic structures, arithmetic abilities and thinking (determination of the sequence of plot pictures, enumeration of objects of one class) were recorded.