The aim of this paper is to present the results of empirical study on reading skills in pupils from IVth to VIth grades of secondary schools. Two aspects of reading skills were examined, i.e. decoding and reading comprehension. We used Ober's et al. Prolexia test, which is divided into two parts. The first part measures the level of decoding (44 chain-words), the second one - reading comprehension (31 chain-sentences). 463 students (248 girls and 215 boys) took part in the research. 30% of them came from IVth grades, 34% from Vth grades and 36% from VIth grades. These students lived in different residential areas: 27% - rural areas, 46% - small towns and 27% - the capital city (Warsaw). Three-way ANOVA indicated that all three factors, i.e. grade (age), sex of the child and type of residential area are significant as far as decoding and reading comprehension are concerned. The interaction 'sex x residential area' was also significant. Differences of decoding between students of IVth, Vth and VIth grades were bigger then differences of reading comprehension. Boys from each grade of rural and small town areas had lower level of both reading skills than girls. Students from Warsaw schools had the highest level of both reading skills. The factor 'residential area' turned out to be significant in the group of boys, but insignificant in the group of girls.