The aim of this study is to examine the mathematics skills of fourth-grade children from Kosovo in relation to their background characteristics. Seventy-six children, out of 233 tested, who were identified with learning difficulties in mathematics were further assessed during fifth and sixth grades, in mathematics skills and reading comprehension. The findings showed that there were no gender differences in mathematics achievement, whereas children's urban or rural locations as well as their socio-economic status were observed to have a substantial impact on mathematics performance of children in the main sample, but not for those in the subsample. For children with learning difficulties in mathematics, the initial level of reading skills was a powerful determinant of their later mathematics performance and the initial level of mathematics skills was also similarly predictive of reading comprehension. The children's background characteristics did not add explanatory variance in performance outcomes over their previous mathematics and reading skills learned during the first years of primary school. The high association between mathematics performance and reading comprehension suggests that mathematics and reading problems may result from a similar cognitive background.