Aim of the study. The aim of this study was to assess the scope and direction of long-term change tendencies in indicators of mental, physical, and motor development, and to assess the correlation between the level of non-verbal intelligence and indicators of physical development and between the level of non-verbal intelligence and selected components of physical fitness (measured according to under the health-related fitness convention) among children aged 4-14 years from different social backgrounds in the Małopolska Province. Material. Observed was the level of motor, somatic, and mental development among girls and boys aged 4-14 years between 2005 and 2010 in three different-sized agglomerations in the Małopolska Province: the city of Kraków, the village of Barcice, and the town of Sławków. A total of 1429 children were assessed, including 202 girls and 217 boys from Barcice, 221 girls and 199 boys from Sławków, and 274 girls and 316 boys from Kraków.Methodology. In accordance with the aim of the study, selected indicators of somatic, motor, and mental development among children were compared to the corresponding data for 1975-1980 from the same agglomerations.