The aim of this study was to compare the costs of three strategies in patients with prostate cancer in a specific setting: firstly, a strategy including MR lymphography (MRL) in which pelvic lymph node dissection (PLND) is foregone in case of a negative result. The second strategy involves computed tomography (CT) followed by a biopsy or PLND. The third strategy consists of PLND without imaging beforehand. A decision analytic model was constructed. This model represented the diagnostic process for patients with prostate cancer and intermediate or high risk for nodal metastases, comparing the costs of the three strategies. Cost analysis was done from the health care perspective. The model indicated that the expected costs for the MRL strategy were 2,527 euro. The expected costs for the strategy using CT were 3,837 euro and for PLND 3,994 euro. These results show that potential savings performing MRL instead of CT were 1,310 euro and 1,467 euro for PLND. Sensitivity analyses show that variation in costs of PLND was most influential on the costs of all strategies. However, the overall savings pattern did not alter. Average costs of MRL staging in our institution are less than for CT and PLND in staging lymph nodes of patients with prostate cancer and who are intermediate or high risk for nodal metastases.