PURPOSE International guidelines advocate for active surveillance as the preferred treatment strategy for patients with stage 1 testicular cancer after orchidectomy although a personalized discussion is required. MATERIALS AND METHODS We conducted an analysis of individuals registered in iTestis, Australia's testicular cancer registry, to describe the patterns of relapse and outcomes of patients treated in Australia where the Australian and New Zealand Urogenital and Prostate Cancer Trials Group Surveillance Recommendations are widely adopted. RESULTS A total of 650 individuals diagnosed between 2000 and 2020 were included, 63% (411 of 650) seminoma and 37% (239 of 650) nonseminoma. The median age was 34 years (range 14-74). 26% (106 of 411) with seminoma and 15% (36 of 239) nonseminoma received adjuvant chemotherapy. After a median follow-up of 43 months (range 0-267) postorchidectomy, relapse occurred in 10% (43 of 411) of seminoma and 18% (43 of 239) of nonseminoma. The two-year relapse-free survival was 92% (95% CI, 89 to 95) and 82% (95% CI, 78 to 87) in seminoma and nonseminoma, respectively. All relapses (86 of 86) were detected at a routine surveillance visit; 98% (85 of 86) were asymptomatic and detected solely through imaging (62 of 86, 72%), tumor markers (6 of 86, 7%), or a combination (17 of 86, 20%). The most common relapse site was isolated retroperitoneal lymphadenopathy (53 of 86, 62%). No nonpulmonary visceral metastases occurred. At relapse, 98% (84 of 86) had International Germ Cell Cancer Collaborative Group (IGCCCG) good prognosis; 2 of 86 intermediate prognosis (both nonseminoma). No deaths occurred. CONCLUSION In our cohort of stage 1 testicular cancer, where national surveillance recommendations have been widely adopted, recurrences were detected at routine surveillance visits and, almost exclusively, asymptomatic with IGCCCG good-prognosis disease. This provides reassurance that active surveillance is safe.