In this longitudinal study, we examined what kind of profiles of reading fluency and spelling skills could be identified among pupils (N = 467) and how stable these profiles were during the first three years of school. We also investigated how monolingual (Swedish) and simultaneously bilingual (Finnish-Swedish) pupils and gender were distributed within the profiles. Three profiles of reading fluency and spelling skills were found among the pupils through latent profile analysis: low, average, and high performing. Latent transition analysis confirmed stable and identical profiles throughout the first school years. The distributions of monolingual and bilingual pupils and gender were equal in all profiles throughout the grades. These findings have implications on a pragmatic level in school, confirming the importance of early identification and support for low performing pupils.