Upper elementary school students who have reading problems may have difficulty in one or more areas of reading, each requiring specific types of interventions. This study evaluated a short-term reading intervention for 46 fifth-grade students with poor reading comprehension. Students were randomly assigned to an intervention or no treatment control condition. The 40 session (20 hr) intervention targeted reading comprehension strategy instruction in the context of informational science texts. Analyses showed statistically significant effects favoring the intervention on two proximal measures (i.e., measures closely related to the intervention content). The effects for the outcomes were moderate (gs = 0.61 and 0.72). There were no statistically significant differences on distal measures (i.e., measures less closely aligned with the intervention). The findings provide support for the efficacy of a reading comprehension intervention that may inform short-term interventions within a Response to Intervention framework.