TGF‐β1 is a cytokine with profibrogenic and immunosuppressive activities, which suggest the clinical significance of TGF‐β1 for the assessment of graft function after LT. We analyzed the dynamics of TGF‐β1 levels in the blood after LDLT in 135 pediatric liver recipients and examined the relationship between the cytokine levels and the laboratory and clinical variables. We found that TGF‐β1 levels in the blood of patients with ESLD were lower than that in healthy children of the same age, P = .001. Moreover, blood levels of TGF‐β1 were associated with liver disease etiology (r = .23) and hepatic fibrosis severity (r = .33). Before LDLT, TGF‐β1 levels were significantly higher in children with good outcomes than in recipients who developed graft dysfunction early in the post‐transplant period, P = .047. One month after LDLT, TGF‐β1 levels in blood plasma increased in pediatric recipients, P = .002. Cytokine levels were significantly correlated with gender (r = .21) and HLA (r = −.24) mismatches, as well as with TAC dosage (r = −.32) later in the post‐transplant period. One year after LDLT, TGF‐β1 plasma levels were higher (P = .01) than those before LDLT and did not correlate with most of the investigated biochemical and clinical variables. Conclusion: Blood levels of TGF‐β1 are associated with hepatic fibrosis severity, graft dysfunction development, and TAC dosage and can be regarded as a potential prognostic biomarker for the assessment of graft function and the optimization of immunosuppressant dosage in pediatric recipients after LDLT.