Objectives. The aim of this study was to determine presence of metacognitive manifestations in the different phases of problem solving and to examine developmental and socio-educational differences in metacognition in preschoolers, with respect to children's gender, age, socioeconomic status of the family, parent's education and type of preschool institution. Sample and settings. The sample included 418 preschool children, aged 3-6 years. Research was conducted in preschool institutions. The conditions were standardized and controlled by researchers - the researcher gave clear instruction to children before each task. Hypotheses. It was assumed that preschool children are able to manifest verbal and nonverbal metacognition indicators and that these manifestations are related to children's age and socio-educational factors, such as socio-economic status of the family, parent's education and type of preschool institution. Statistical analysis. Descriptive statistics were used to determine presence of metacognitive manifestations. Two-factorial ANO VA was applied to examine gender and age differences. The post-hoc analysis (GLM) was conducted to test influence of socio-educational factors. Results. It is showed that preschoolers use verbal and non-verbal metacognitive responses in different phases of problem solving. Older children manifested more indicators of metacognition. Also, socio-economic status of the family and parent's education showed as significant factors which contribute to differences in metacognitive manifestations in preschoolers. Study limitations. Metacognition was measured without testing strategies which could enhance it, so future research would test influence of these strategies on development of metacognition in preschoolers.