Objective To assess long-term secular trends in the utilization of bilateral compared with unilateral orchiectomy in the community. Patients and Methods This population-based descriptive study reviewed medical records of all Olmsted County, Minnesota, men undergoing orchiectomy between 1956 and 2000. Results Over the 45-year study period, 381 Olmsted County men had a first unilateral orchiectomy, while 431 underwent bilateral orchiectomy (including 8 with a second unilateral orchiectomy). There was no change over time in the age-adjusted utilization of unilateral orchiectomy, which was performed for a wide range of indications, mostly cryptorchidism and testicular malignancy. Most bilateral procedures, on the other hand, were in elderly men for castration, and trends over time generally paralleled those reported for prostate cancer in this community. Conclusion The declining incidence of prostate cancer in recent years, combined with a shift to earlier stages and younger ages at diagnosis, and the development of pharmacological approaches to hormonal manipulation have led to a dramatic decline in the utilization of bilateral orchiectomy, while unilateral orchiectomy rates have remained unchanged.