In view of contrary reports in the literature on anomalies of taurine concentration in the blood of retinitis pigmentosa patients, taurine clearance has been determined in 19 patients and 17 controls. No significant difference has been found between the average values of the two populations. The taurine content in cataractous crystalline lenses of retinitis pigmentosa patients has been found higher than the taurine content in lenses with senile cataract, but the same behaviour was also shown by five selected proteogenic amino acids. The results are discussed together with related literature data to conclude that taurine can be involved at least in some subtypes of retinitis pigmentosa, but cannot be considered as a marker for the disease.