Whether TLX3 is a predictor of prognosis of pediatric T cell acute lymphocytic leukemia (T-ALL) is controversial, with some studies concluding that it is and others concluding the opposite. Therefore, a systematic review was performed to explore the relationship of TLX3 expression with the prognosis of pediatric T-ALL. The PubMed database, The Cochrane Library, conference proceedings, EMBASE databases, and references of published trials and review articles were searched. Two reviewers independently assessed the quality of the trials and extracted data. Hazard ratios (HRs) for disease-free survival (DFS) and odds ratios (OR) for 5-year DFS were pooled using the STATA package. Ultimately, six trials involving 515 patients with pediatric T-ALL were analyzed. The pooled HR (1.07 [0.32, 3.56], p = 0.91) for DFS and OR (1.30 [0.52, 3.27], p = 0.57) for 5-year DFS showed that the TLX3-positive group showed no statistically significant difference with the TLX3-negative group. Our results suggested that TLX3 expression is not an indicator for the prognosis of pediatric T-ALL.