Research has been carried out on the metabolism of thiamine chloride ester monophosphate of bis-D-glucosamine (TCMPG) evaluating the urinary excretion, the blood and the hepatic content of thiamine in the rat after intraperitoneal injection of this compound. The results obtained have shown a greater retention of vitamin B1 when it is administered as glucosamine salt. In fact, the amount of thiamine excreted by the rats which have received the TCMPG is lower while the blood and liver levels of vitamin are higher, compared with the control rats treated with thiamine monophosphate only, or with thiamine and glucosamine. These results permit the conclusion that glucosamine increases the utilization of the vitamin and its penetration into the cells.