The purpose of this study was to investigate the use of a critical thinking rubric as an assessment of reading achievement for students enrolled in a reading intervention course. A reading prompt and scoring rubric, based on Richard Paul and Linda Elder's critical thinking framework, were created to assess critical reading in an intervention course. The prompt and rubric were used throughout the semester to provide formative reading assessment. The scoring rubric, which is responsive to reading as a cognitive process, was also used for precourse and postcourse assessment to provide a unique measure of reading achievement that incorporates the university's critical thinking initiative. A repeated measures design was used to assess the reading achievement of 164 students on five different reading prompts over the course of a fall semester. Results showed significantly higher postassessment rubric scores (p less than 0.001) and a significant change in rubric scores over time (p less than 0.05). (Contains 3 tables and 8 figures.)