Introduction: Richner-Hanhart syndrome (tyrosinemia type II) is a rare autosomal recessive disease associated with high serum tyrosine levels caused by the deficiency of tyrosine ami-notransferase enzyme.

 Case Report: We report a 7-year-old female patient with complaints of hyperkeratosis lesions of palms and soles which started 3 years ago. Chromatography of serum amino acids showed a tyrosine level of 120micromole/L (normal range: 22-87). She had normal ophthalmologic examination and mild mental retardation was detected. One month after the tyrosine- and phenylalanine-restricted diet, her tyrosine level dropped to 42 micromol/L level, her keratotic lesions subsided, and a symptomatic relief in learning was achieved.

Conclusion: Tyrosinemia type II should be suspected in patients demonstrating dermatologic signs, especially palmoplantar keratosis, associated with bilateral pseudodendritic corneal lesions unresponsive to antiviral therapy and mild to moderate mental retardation, although our patient without ophthalmic lesions is a very rare case of this syndrome.