Research has demonstrated that oral reading fluency probes are reliable and valid for indexing reading achievement. If these probes are to be used for decision making, bias must be examined for various factors, including ethnicity, gender, language background, and socioeconomic status. Data from nearly 4,000 Caucasian and Hispanic students in grades one through three were used to examine potential bias in oral reading fluency scores predicting Stanford Achievement Test-Ninth Edition (SAT-9; Harcourt Brace & Co., 1997a, 1997b Total Reading scores. Using a series of hierarchical multiple regression models, bias was first examined using concurrent SAT-9 scores as the criterion and then examined using subsequent SAT-9 scores as the criterion. The results reveal that it is the combination of factors, not any one in isolation, that significantly contributes to intercept bias findings. Overall, home language emerged as the strongest factor influencing bias in the prediction of SAT-9 scores from oral reading fluency scores. The implications of these findings are discussed as related to current and proposed uses of oral reading fluency probes.In 1977, research was undertaken at the University of Minnesota to develop simple measures of reading performance (Deno, 1985). The result was a methodology traditionally referred to as curriculum-based measurement (CBM) of reading. This methodology involves having students orally read brief passages of text to determine oral reading fluency (Deno, 1985;Shinn, 1998). Decades of re-The authors would like to express their appreciation for the tremendous efforts of the ORAL-J research team at UCSB, including graduate students and undergraduate research assistants.