Patriot High School (PHS) adopted a remediation strategy to help its 10th-grade students at risk of failing the Math portion of MCAS, the state's end of year competency exam. The centerpiece of that strategy was a computer-based instructional (CBI) course. PHS used a commercially available CBI product to align the course content with the competencies covered on the MCAS exam. This case study examines the overall effectiveness of the PHS strategies, and in particular, the role of CBI. Participant MCAS scores and CBI performance (measured by module-mastery data) are analyzed, and an interview with the course instructor is summarized. Finally, PHS scores were compared to the overall state MCAS scores for the same years. Overall scores of all 10th graders increased significantly compared to their 8th-grade scores, students who participated in the CBI course improved more than the students who did not. The passing rate at PHS improved from 40% in 1999 to 84% in 2001, compared to an improvement of from 47% to 75% statewide. A significant correlation was identified between the MCAS scores and the program usage data, with student CBI module mastery correlated with higher MCAS scores. Overall, the instructor was positive about the impact of the course and believed that the course gave many under-performers a chance to succeed when more traditional methods had failed. It seems likely that CBI contributed to PHS's success. Although we report herein on just one case, we argue that CBI might play an important a role in the high stakes test environment in the USA and elsewhere.