This longitudinal study examined the relations between self-regulation and reading achievement from kindergarten through second grade. In addition to the broader concept of effortful control, this study looked at various sub-components, including attention focusing and inhibitory control. A series of unconditional latent growth curve models were estimated to assess the initial level and growth of children’s parent- and teacher-reported effortful control and reading skills. In addition, parallel-process latent-growth curve models were estimated to examine the relations between the growth parameters (e.g., how the initial level and growth in self-regulation relates to the initial level and growth in reading). Parent-reported inhibitory control and effortful control displayed linear growth over this time period. Teacher-reported self-regulation did not change significantly. Reading achievement increased across all three time points, but the rate of growth was steeper from kindergarten through first grade than from first to second grade. Results from the parallel-process models showed that the kindergarten scores for parent-reported attention focusing and inhibitory control were negatively related to growth in Letter Word abilities from first through second grade, whereas initial teacher-reported attention focusing, inhibitory control, and effortful control were negatively related to growth in Passage Comprehension abilities from first to second grade. This study illustrates important relations between self-regulation and reading abilities throughout the first few years of elementary school.