Objective: To report our experience of a contemporary series of patients who underwent radical orchidectomy for non-palpable testicular masses, in order to comment on their malignant potential and identify any factors predictive of a malignant outcome. Materials and Methods: We reviewed the case-notes of patients who underwent radical inguinal orchidectomy over a 22-month period between January 2010 and October 2011. Results: A total of 71 patients were analysed, with a mean (range) age of 45 years (17 - 82). Overall, 41 (57.7%) orchidectomies were malignant and 30 (42.3%) were benign. There were 20 (28%) non-palpable testicular masses found incidentally on ultrasound, and of these 40% were malignant and 60% were benign. In total 6 of these non-palpable lesions were <1 cm in size, and of these 66.6% were malignant and 33.3% were benign. The majority of tumours were in patients under the age of 50, but there was no correlation between the lesion size and the risk of a malignant outcome. Conclusion: In view of the significant rate of malignancy in non-palpable testicular masses we recommend surgical intervention over surveillance alone. However, as the majority of these lesions may eventually turn out to be benign, we suggest that testis-sparing surgery is the optimal approach, and should be performed in centres where the required radiological, histopathological, and surgical expertise exists.