This study applied an early screening approach to determine the risk status of children in 5 urban schools and monitor their patterns of reading growth over 3 years. A majority of students were from culturally diverse and low-SES backgrounds. Two validated instruments were used for determining (a) academic risk (the Dynamic Indicators of Basic Early Literacy Skills [DIBELS]; Good, Simmons, & Smith, 1998) and (b) behavioral risk (Systematic Screening for Behavior Disorders [SSBD]; Walker & Severson, 1992, or Early Screening Project; Walker, Severson, & Feil, 1995). DIBELS data for 383 students were used to determine the characteristics and effectiveness of reading curriculum reforms for students in kindergarten through 2nd grade. Results indicated that students with a single risk factor (academic or behavioral) progressed more slowly than the general population in the participating schools. The students with behavioral risks, however, made better progress, becoming more fluent readers than the students with academic risks. Students with both academic and behavioral risks made the least progress. "The Reading Mastery" curriculum (Reading Mastery, 1995) produced better growth in reading fluency than did "Success for All" (Success for All, 1999) or the literature-based curriculum. It also produced better growth for students with academic, behavioral, or both risk factors. The "Success for All" curriculum produced less growth compared to the "Reading Mastery" curriculum but was superior to the literature-based curriculum. Implications are discussed. (Contains 4 tables and 3 figures.)