The purpose of this study was to examine the validity evidence of first-grade Dynamic Indicators of Basic Early Literacy Skills (DIBELS) scores for predicting third-grade reading comprehension scores. We used the “simple view” of reading as the theoretical foundation for examining the extent to which DIBELS subtest scores predict comprehension through both word recognition and language comprehension. Scores from the DIBELS Oral Reading Fluency (ORF) subtest, a measure of word recognition speed and accuracy, strongly and significantly predicted multiple measures of reading comprehension. No other DIBELS subtest score explained additional variance beyond DIBELS ORF. Although experimental DIBELS Word Use Fluency (WUF) was significantly correlated with a language comprehension measure and measures of reading comprehension, WUF scores did not predict reading comprehension beyond ORF scores. Alternatively, first-grade Peabody Picture Vocabulary Test scores did predict additional, significant variance in reading comprehension, beyond DIBELS ORF.