Background: It has been suggested that children's writing is dependent on transcription and executive functions. However, there is a need for more research examining the relationships among those variables in primary school children, given that most existing studies are cross-sectional and assess transcription and executive functions separately, and there are scarce and mixed longitudinal findings. Aims: This study used a cross-lagged panel model to explore the relationships among transcription skills, executive functions and text quality from Grade 2 to Grade 3. Sample: The sample included 353 Portuguese children (195 boys, 155 girls) in Grade 2, who were reassessed in Grade 3. Methods: Children were assessed on transcription, executive functions and writing tasks at two time points. Results: Transcription skills and executive functions in Grade 2 positively predicted the same variables in Grade 3. At Grade 2, transcription skills were associated with executive functions and text quality. At Grade 3, we only found an association between executive functions and text quality. Finally, text quality in Grade 2 predicted transcription skills in Grade 3, but both transcription and executive functions in Grade 2 did not predict text quality in Grade 3. Conclusions: Transcription skills and executive functions seem to be stable over time, but previous performance on these skills does not seem to predict later text quality. Overall, these findings do put into question the direction of the typically assumed relationships, especially between transcription and text quality. Findings also provide information that can guide the development of instructional programmes in primary school.