Introduction: We estimate the lifetime cost of treatment for moderate/severe symptoms associated with benign prostatic hyperplasia (BPH) in a cohort of Canadian men aged 50 to 59, and we evaluate the costs of 2 daily bioequivalent treatment options: fixed-dose combination (FDC) of dutasteride (0.5 mg) and tamsulosin (0.4 mg), or concomitant administration of dutasteride (0.5 mg) and tamsulosin (0.4 mg) monotherapies.Methods: The expected lifetime costs were estimated by modelling the incidence of acute urinary retention (AUR), BPH-related surgery and clinical progression over a patient’s lifetime (up to 25 years). A model was developed to simulate clinical events over time, based on a discrete Markov process with 6 mutually exclusive health states and annual cycle length.Results: The estimated lifetime budget cost for the cohort of 374 110 men aged 50 to 59 in Canada is between $6.35 billion and $7.60 billion, equivalent to between $16 979 and $20 315 per patient with moderate/severe symptoms associated with BPH. Costs are lower for FDC treatment, with the net difference in lifetime budget impact between the 2 treatment regimens at $1.25 billion. In this analysis, the true costs of BPH in Canada are underestimated for 2 main reasons: (1) to make the analysis tractable, it is restricted to a cohort aged 50 to 59, whereas BPH can affect all men; and (2) a closed cohort approach does not include the costs of new (incident) cases.Conclusion: Canadian clinical guidelines recommend the use of the combination of tamsulosin and dutasteride for men with moderate/severe symptoms associated with BPH and enlarged prostate volume. This analysis, using a representational patient group, suggests that the FDC is a more cost-effective treatment option for BPH.