This longitudinal study aimed to investigate the extent to which primary school text comprehension predicts mathematical word problem-solving skills in secondary school among Finnish students. The participants were 224 fourth graders (9-10 years old at the baseline). The children's text-reading fluency, text comprehension and basic calculation ability were tested in grade four. In grade seven and nine, their skills in solving mathematical word problems were assessed. Overall, the results showed that text comprehension in grade four of primary school predicts math word problem-solving skills in secondary school, after controlling for text-reading fluency and basic calculation ability. Among boys, good text comprehension skills in grade four predicted good math word problem-solving skills in grade seven. Among girls, good text comprehension skills in grade four predicted their subsequent mathematical word problem performance in grade nine. The practical implications of the results are discussed as well.