A study tested the effects of an approach for improving reading fluency on the general reading and fluency development of second-grade students in regular classrooms. Subjects were from two elementary schools in a large, urban, ethnically diverse school district. There were 30 students in 2 classrooms in a school located in a working class residential setting and 24 students in 2 classrooms in a school located in an inner-city neighborhood. One classroom in each school employed the Fluency Development Lesson (a 10- to 15-minute instructional activity that incorporates several key principles of effective fluency instruction) daily for 6 months. The other classroom in each school was given a control treatment. Pre- and posttesting consisted of subjects being administered a modified informal reading inventory. Results indicated that, aside from improvements in oral reading rate, no other statistically significant treatment effects were observed. However, results also indicated that: (1) all subjects in the study (particularly the experimental subjects) read at a rate above second-grade norms at the posttest; (2) experimental subjects' oral reading rate was higher than normal for some passages; (3) experimental subjects increased their reading rate at a much greater rate than normal; and (4) experimental group teachers reported significant improvements in students' reading performance and attitude. Findings suggest that specific lessons directed at improving reading fluency may be of some value for early elementary grade readers. (Six tables of data are included; 30 references are attached.) (RS)