The purpose of this study was to compare the effect of two theoretically different reading programs on the reading outcomes of first-grade students (N = 107). Two elementary schools were chosen for participation based on the first-grade reading program currently being implemented in the schools. One school used the "Horizons Fast Track A-B" reading program and the other used a Guided Reading approach. Students were assessed on Phoneme Segmentation Fluency, Nonsense Word Fluency, and Oral Reading Fluency using the AIMSweb (Edformation, 2006) progress monitoring system. Results showed differing responses to the interventions. Students in both conditions significantly increased across time on Phoneme Segmentation Fluency, Nonsense Word Fluency, and Oral Reading Fluency. However, the students in the Guided Reading condition significantly outperformed the students in the "Horizons" condition on Phoneme Segmentation Fluency, while the students in the "Horizons" condition made significantly greater gains than students in the Guided Reading condition on Oral Reading Fluency. Results are discussed in regards to the differences between the two reading programs. (Contains 1 table and 3 figures.)