ABSTRACT Background and objective T-cell acute lymphoblastic leukemia (T-ALL) in children represents a high-risk disease. There is a lack of studies assessing the outcome of T-ALL in Hispanic populations, in which it is a rare malignancy. We report the characteristics and results of treatment for childhood T-cell ALL in children over 14 years at a Latin American reference center. Material and methods From January 2005 to December 2018, there occurred the analysis of twenty patients ≤ 16 years of age from a low-income open population diagnosed at a university hospital in Northeast Mexico. Clinical and laboratory characteristics, treatment regimens and outcomes were assessed by scrutinizing clinical records and electronic databases. Diagnosis was confirmed by flow cytometry, including positivity for CD-2, 5, 7 and surface/cytoplasmic CD3. Survival rates were assessed by the Kaplan-Meier method. Results There was a male preponderance (70 %), with a 2.3 male-to-female ratio (p= .074), the median age being 9.5 years. Leucocytes at diagnosis were ≥ 50 × 109/L in 13 (65 %) children, with CNS infiltration in 6 (30 %) and organomegaly in 10 (50 %). The five-year overall survival (OS) was 44.3 % (95 % CI 41.96-46.62), significantly lower in girls, at 20.8 % (95 % CI 17.32-24.51) vs. 53.1 % (95 % CI 50.30-55.82), (p= .035) in boys; there was no sex difference in the event-free survival (EFS) (p= .215). The survival was significantly higher after 2010 (p= .034). Conclusion The T-cell ALL was more frequent in boys, had a higher mortality in girls and the survival has increased over the last decade with improved chemotherapy and supportive care.