Abstract: The cumulative urinary excretion of two domestic-made hydrochlorothiazidetablets(A and B) was determined in seven healthy men after oral administrationof 75mg of the drug. The relative bioavailability of hydrochlorothiazide tabletsA and B compared with that of FDA standard reference hydrochlorothiazaide tablets was 95.09% and 77.70% respectively. The total recovery of hydrochlorothiazaide from A and B in urine was 49.89% and 40.71% respectively.