The aim of this longitudinal study was to investigate the developmental antecedents of reading performance and its subcomponents from the beginning of the first year to the end of the second year of primary school. One-hundred-and-fourteen seven-year-old Finnish-speaking children were tested on reading-related skills during their first week of school using a test battery designed for school entrants. Following this they were examined six times on word reading and reading comprehension skills. The results showed that the reading-related variables predicting reading performance varied according to the phase of reading development. Moreover, partially different antecedents predicted word reading and reading comprehension. Word reading was associated with letter knowledge and listening comprehension, whereas initial word reading skill and listening comprehension were highly associated with the development of reading comprehension. The results support the development of reading instructional methods that take into account these differences in the components of reading performance and their development.