In discussions of the merits and limitations of problem-based learning (PBL) as an educational methodology, the cost of its delivery is often cited as a significant issue. Although there appears to be no shortage of opinion as to the perceived cost of PBL, we know of no institution that has accurately measured its cost, even in financial terms. Where factual information is lacking, opinion and misconception tend to proliferate. In setting up a new, graduate-entry medical programme on a greenfield site at the University of Limerick, we took the opportunity to calculate both the initial and recurring costs of our particular approach to the delivery of PBL. We calculated the initial cost of providing purpose-built facilities to deliver PBL to 240 students in the first 2 years of our 4-year programme. We also calculated the annual recurring costs of delivering PBL, based on having a student : tutor ratio of 8 : 1 and on having tutors who are all medically qualified, who are reasonably well remunerated for their work and who each deliver 5 hours of PBL tutoring per week. The initial cost of delivering PBL was calculated as euro 1,526,952 (equivalent to pound sterling 1,369,138 or US$2,050,375). The annual recurring cost of PBL approximates euro 664,000/year (at time of writing equivalent to pound sterling 527,000 and US$988,000). This recurring cost equates to euro 2767/student/year, 89% of which relates to tutor salaries. Although the cost of delivering PBL will be greatly influenced by the approach taken at different institutions, we hope that a breakdown of costs at our institution will contribute to the ongoing debate on the strengths and weaknesses of PBL.