Background: Notwithstanding excellent oncological outcomes reported by pivotal trials in patients with testicular germ cell tumors (TGCT), adherence to medical treatment and follow-up remains a major issue in developing countries. Studies that describe the clinical characteristics and treatment adherence of Mexican men with TGCT are lacking. Methods: We performed a retrospective analysis of all men with newly diagnosed TGCT treated at an oncology referral center in Northeast Mexico from 2014 to 2018. Results: In the analysis, 195 patients were included. Median age at diagnosis was 28 years; median time from diagnosis to first evaluation by an oncologist was 26 days. Distribution according to the laterality of the primary tumor was right, 56%; left, 43%; and bilateral, 1%. There were 14 oncological emergencies at presentation; the most frequent was choriocarcinoma syndrome, described in 5 patients. Thirty-five percent of cases were seminomatous germ cell tumors (SGCT) and 65% nonseminomatous germ cell tumors (NSGCT). The clinical stages at diagnosis were I, 36%; IS, 8%; II, 18%; and III, 38%. After risk stratification according to the International Germ Cell Cancer Collaborative Group (IGCCCG), 90% of SGCT had a good risk and 10% an intermediate risk. In NSGCT, the risk distribution was 65, 10, and 25% for good, intermediate, and poor-risk disease, respectively. After proposing treatment, the adherence rate was 81%. Of the total, 58% were lost to medical follow-up with a median time of adherence of 11.5 months. Conclusions: Despite coverage by the Mexican public health insurance system “Seguro Popular”, treatment adherence and medical follow-up abandonment is a problem among men with TGCT, which could negatively impact their prognosis. Measures must be implemented to optimize adherence in this group of patients.