Objective: To investigate well-controlled congenital hypothyroidism on the markers associated with early kidney injury and oxidative DNA damage.Methods: Twenty-three children with euthyroid congenital hypothyroidism aged 3–6 years and 19 age- and gender-matched controls were enrolled. Serum levels of albumin, C-reactive protein, cysteine C, globulin, pre-albumin, and total protein were detected. Urine levels of albumin, fibrin degradation products, IgG, β2-microglobulin, and 8-hydroxydeoxyguanosine (8-OHdG) were also measured. Clinical and biochemical characteristics were evaluated between the two groups.Results: Serum levels of C-reactive protein were higher, but pre-albumin was lower in patients with congenital hyperthyroidism compared with the controls (all pConclusion: It is concluded that inflammatory and oxidative markers were slightly altered in well-controlled congenital hypothyroidism. The levels of urinary 8-OHdG and albumin excretion were not significantly different.