OBJECTIVES: The aim of this study was to assess the cost-effectiveness of imiquimod cream 5%, in the treatment of superficial basal cell carcinomas (sBCC) compared to usual care in Norway. METHODS: The cost-effectiveness analysis was performed using a decision model, comparing imiquimod, a topical immune response modifier, with usual care in a Norwegian practice setting. Estimates of initial clearance and recurrence in sBCC are from randomized clinical trials of imiquimod and from literature reviews supplemented by assessments from structured interviews with clinical dermatologists. RESULTS: Dermatologists reported the distribution of treatment options for sBCC in Norway as surgery (30%), cryosurgery (40%) and photodynamic therapy (30%). A weighted composite outcome of these three alternatives (usual care) was used as basis for the comparison. Adverse events and their consequences in terms of treatment costs were considered in the model. The model estimates of initial clearance with imiquimod compared to usual care in sBCC was 94% vs. 88%. The analysis found imiquimod to be slightly more expensive per patient (NOK133 per year). The incremental cost-effectiveness ratio (ICER) for imiquimod compared to usual care was NOK1973 per recurrence avoided based on a 1-year time perspective. For individual therapy options, imiquimod dominated PDT, was more expensive but with better outcomes than cryosurgery, yet was dominated by excision surgery. CONCLUSION: The total cost of treatment with imiquimod was marginally higher than the weighted average for usual care, but the treatment with imiquimod substantially reduced recurrence of sBCC. Similar to most other measures of effect, there are no general accepted levels for the societies' willingness to pay for avoided recurrences of sBCC; even so, based on this analysis it is reasonable to conclude that imiquimod provides a cost-effective treatment option for sBCC in Norway.