Colorectal cancer is the third most common cancer in Canada with approximately 16,500 new cases in 1999. Currently, 5-fluorouracil (5-FU) plus leucovorin is standard chemotherapeutic treatment. Raltitrexed, is a new class of cytotoxic drug. OBJECTIVE: To measure from a Canadian Ministry of Health perspective the economic value of raltitrexed 3 mg/m2 once every three weeks and 425 mg/m2 5-FU plus 20 mg/m2 leucovorin for 5 days repeated every 28 days. Results of the study, a large North American trial, are reported elsewhere. In this abstract, results of Canadian patients are reported; specifically, cost per quality adjusted survival. METHODS: Quality adjustments were conducted by rewarding survival time without toxicities and disease progression while penalizing time with toxicities or disease progression. Healthcare costs by type of resource and economic perspective were collected from five centers that participated in the clinical trial in Quebec and Ontario. RESULTS: 103 patients were eligible for analyses, 50 in the 5-FU+LV group and 53 in the raltitrexed group. Without adjustment for quality versus quantity of survival, the median time to death from Kaplan Meier estimates were equivalent 496 and 493 days, respectively. Both time to progression and time with toxicities favored patients treated with raltitrexed. Thus, quality adjusted survival favored patients treated with raltitrexed, 269 versus 370 days at the median. Direct drug cost favored 5-FU+LV, $130 versus $1,005 for an average cost difference of $875; nonetheless, the incremental cost per QALY for raltitrexed was $3,159 (95%CI: $1,626-$4,692). When other direct medical costs were included raltitrexed became cost saving. CONCLUSIONS: Raltitrexed offers a more convenient treatment regimen than 5-FU plus leucorvorin and is as effective while causing less toxicity.