The present longitudinal study aimed to investigate the influence of ADHD symptoms on reading development in elementary schoolchildren. To this end, repeated assessments of ADHD symptoms (teacher ratings of inattention, hyperactivity, and impulsivity) and reading achievement (standardized tests of decoding speed and text comprehension) were examined in a sample comprising 2,014 elementary schoolchildren at the end of Grades 1, 2, 3, respectively, and in the middle of Grade 4. Latent change score models revealed that the level of ADHD symptoms was associated with lower levels and less growth in decoding speed and text comprehension. Furthermore, individual differences in changes in ADHD symptoms and reading performance were negatively associated. Together, these results indicate commonalities in the development of ADHD symptomatology and reading achievement throughout elementary school.