Initial reports on HemoQuant, a new quantitative test for occult gastrointestinal bleeding, suggest it is more sensitive than Hemoccult. Increased detection of upper gastrointestinal tract bleeding and dietary hemoglobin may reduce HemoQuant's specificity in the screening setting. The authors performed a cost effectiveness analysis comparing Hemoccult and HemoQuant for colorectal cancer screening using assumptions based on probabilities and costs in the current literature, varying the specificity of HemoQuant. The analysis showed the marginal cost effectiveness of Hemoccult versus no test to be $43,000, and HemoQuant versus Hemoccult to be $296,000 if HemoQuant specificity is 0.95. The marginal cost effectiveness ratio increased to $601,000 if three HemoQuant tests were used. Survival benefit was small and highly dependent on Hemoccult sensitivity and mortality from colonoscopy if HemoQuant specificity was less than 0.9. The authors conclude that unless the high sensitivity reported for HemoQuant is accompanied by a specificity comparable to that of Hemoccult, HemoQuant may not be an acceptable alternative for colorectal cancer screening.