A nuclear medical diagnosis apparatus capable of attaining improvement of the sensitivity by the reduction of a count loss of the data is provided. A data sort section inside a data acquisition unit re-arranges and outputs the data packet from a plurality of auxiliary data acquisition unit in order of the detection time data. A coincidence detection section includes a pair check section and a pair generation section. The pair check section refers to a context on the data packet re-arranged in order of the detection time, and judges a pair relating to a coincidence counting. The pair generation section, based on this judgment result, merges the data packet used as a pair, and outputs the same to the collection work station.