The purpose of this research brief is to present results from a study investigating the relation between word reading fluency (both initial level and fall-winter gain scores), passage reading fluency, and reading comprehension. Word reading fluency data were collected in the fall and winter; outcome measures were administered in the spring of Grade 1 (N = 150 students). We found that both initial level and gains on the word reading fluency measure predicted important reading outcomes in Grade 1 and that the impact of gains was attenuated for students with strong initial skills. These findings are consistent with previous research on fluency-based measures of early reading skill.