[en] The medical use of ionizing radiation contributes significantly to population exposure to radiation. This study aimed to evaluate the diagnostic procedures carried out in nuclear medicine (SMN) in Pernambuco and Alagoas in order to gather data to subsidize the proposal of reference levels for nuclear medicine in Brazil. Data were collected of the SMN in Pernambuco and Alagoas in the period of 2005 to 2009, according by UNSCEAR. The study used data from IBGE. The results showed that the total number of examinations in the period 2005 to 2009 was 34.828 in Pernambuco and 27.700 in Alagoas, corresponding to 6.966 and 5.540 average annual examinations in Pernambuco and Alagoas, respectively. The total number of examinations performed in both states in 2009 was twice the number carried out in 2005. Scintigraphy is the cardiovascular examination most performed in both states, followed by bone scintigraphy. Tc-99m is the radionuclide used most often, followed by I-131. The number of tests using Tc-99m in 2009 doubled when compared with the examinations performed in 2005. The results indicate that there has been a significant increase in the number of examinations in MN, and that females outnumber males, as far as the use of this diagnostic resource is concerned. The study of the activities of the radionuclides administered to patients in the states of Pernambuco and Alagoas showed that they are high when compared to the values recommended by the IAEA in its Safety Report Series Document No. 40. (author)