The aim of the study was to analyse literacy instruction activities and their associations with the reading performance of first graders in Estonia and Finland, two countries that share similar orthographies and educational systems but differ in the onset of formal reading instruction. The contents of 33 Literacy lessons in first grade spring were analysed and students’ (NEST = 415, NFIN = 154) reading performance was assessed in first grade autumn and spring. The results showed that there were more similarities than differences between the countries in literacy instruction activities, but some country-specific interaction effects were found between students’ reading performance and contents of the instruction. Especially the slopes of reading performance development among Finnish beginning readers differed from the other readers in both countries with respect to the content of literacy instruction. The results highlight the importance of responsiveness to students’ needs in early school years literacy instruction.