Past research has failed to recognize motivation for its potential to produce instructional gains, especially for students with reading disabilities/difficulties (RD). To this purpose, a combined motivational intervention was administered to 80 second-grade through fifth-grade students in a randomized pretest-posttest control group design with three population groups and two conditions. The intervention condition described a positive label (e.g., "clever") associated with specific reading behavior (e.g., answers questions) accompanied by a challenge to perform better than before and better than another (intrinsic and extrinsic goals). While controlling for initial reading differences, the intervention improved the fluency and comprehension for the RD group, with and without attention deficit hyperactivity disorder (ADHD), relative to the no disability (ND) group, even though the ND group also made gains. These findings documented a first-tier empirically based intervention with practical applications for elementary students with RD and their peers, although gains in reading for the ADHD group without RD were not significant. (Contains 4 tables and 2 figures.)