We report a case of 10-year-old boy with chronic tubulo-interstitial nephritis (TIN). He had febrile convulsion and received sodium valproate (VPA) treatment. 18 months later, he had developed Fanconi syndrome. On admission, he also had evidence of tubular and glomerular dysfunction. Renal biopsy revealed interstitial nephritis with linear tubular-basement-membrane deposition of IgG and C3 and dominant infiltration of CD4 positive cells in interstitium. Although there is not a positive proof of the etiology in the relationship between TIN and VPA, it is likely that VPA is a possible cause of chronic TIN from his past history.