For a study, researchers sought to determine the rate of tumoral PD-L1 expression in Wilms tumor (WT) and analyze the relationship between PD-L1 and tumor invasion and metastasis. About 77 patients with WT were included in the study, including 20 cases of primary WTs with corresponding excised invasive/lymph node metastatic tumors. The expression of PD-L1 in tumors was examined using immunohistochemistry. The link between tumoral PD-L1 expression and follow-up data was investigated using a Kaplan–Meier analysis. Positive tumoral PD-L1 expression was found in 28.6% of primary WT tissues and 35% of related invasive/metastatic tissues. In primary WTs, tumoral PD-L1 expression was linked to late-stage and poor histology (P=0.007; P=0.002). The rate of tumoral PD-L1 expression was higher in the progression group (P=0.038) than in the group without distant metastasis or relapse. The rate of PD-L1 word was similar in primary WTs and matched invasive/metastatic tissues (P=0.435). Tumour PD-L1 expression was linked to disease-free and overall survival (P=0.02 and 0.03). After controlling for histology and tumor stage, tumor PD-L1 expression was correlated with DFS and OS in univariable models but not in multivariable Cox regression. Although PD-L1 expression was associated with recognized prognostic markers in our study, its utility as a prognostic marker and therapeutic target, if any, might be demonstrated later.