The results of the quality control of 99mTc-DPD produced during five consequtive years are statistically evaluated. Radiochemical purity of the kit determined in 75 batches was 98.3±1.3%. TLC on silica gel with the mixture of acetone and methanole (1:1, v/v) was used to determine the content of free pertechnetate. The labeled complex and 99mTc-hydrolyzate was separated by using ascending paper (Schleicher & Schull) chromatography and lN NaCl as the mobile phase. Reliable results were obtained showing that the content of the impurities 99mTc-pertechnetate and 99mTc-hydrolyzate is 1.7±1.3% and 3.4±2.1%, respectively. The biodistribution depends on the quantity of DPD. For the animal experiments its content should be 70–80 g/kg b.w. The experiments revealed that the mean value of bone distribution was 8.8±1.9%/g and in muscles 0.043± 0.42%/g. The uptake in liver and kidneys was below 3%, i.e., 0.65±0.29 and 1.71±0.68%/organ, respectively. The bone/muscle ratio should be at least 160. The analysis shows that the obtained values are arranged around their, statistically allowed, mean values.