Purpose We have evaluated, using a software tool for monitoring and tracking radiation dose, the radiation exposures in hybrid myocardial perfusion imaging (MPI) before and after the optimization of the SPECT/CT acquisition protocol. Methods and materials Examination data was collected from a SPECT/CT scanner Siemens Symbia T6 using Radimetrics version 2.6 (Bayer HealthCare, Whippany, NY). Data of MPI performed between 1st March 2016 and 1st March 2017 have been extracted from the DICOM header and Dose Report files produced by the scanner and stored in PACS. All analysis were made for exams in two days (TD) and in single day (SD). CTDIvol, DLP, SSDE, administered activity and Effective Dose were collected. A new optimized acquisition protocol was created changing CT parameters (mAs and pitch) and defining a new administered dose activity card with a reduction of the administered dose of about 18% for TD protocol and of only 4% for SD protocol because it was already well optimised. Examinations performed between 29th May 2017 and 30th November 2017 have been extracted and all dosimetric param eters were compared between old and new protocol. Results The dose reduction for CT part of the MPI was approximately 52% for all the parameters analysed (CTDIvol, DLP, SSDE, Effective Dose) both for TD and SD protocol. The dose reduction for SPECT part was aligned with the reduction introduced in the new administered dose activity card. In MPI study we have achieved, with the new optimized protocol, a total dose reduction of about 30% in TD exams and of about 24% in SD exams (see table below). Conclusion Using a software tool for monitoring and tracking radiation dose was possible to monitor, in real time, radiation exposure in SPECT/CT exams and analyze how to optimize the protocol to reduce effective dose to the patients. We have evaluated, using a software tool for monitoring and tracking radiation dose, the radiation exposures in hybrid myocardial perfusion imaging (MPI) before and after the optimization of the SPECT/CT acquisition protocol. Examination data was collected from a SPECT/CT scanner Siemens Symbia T6 using Radimetrics version 2.6 (Bayer HealthCare, Whippany, NY). Data of MPI performed between 1st March 2016 and 1st March 2017 have been extracted from the DICOM header and Dose Report files produced by the scanner and stored in PACS. All analysis were made for exams in two days (TD) and in single day (SD). CTDIvol, DLP, SSDE, administered activity and Effective Dose were collected. A new optimized acquisition protocol was created changing CT parameters (mAs and pitch) and defining a new administered dose activity card with a reduction of the administered dose of about 18% for TD protocol and of only 4% for SD protocol because it was already well optimised. Examinations performed between 29th May 2017 and 30th November 2017 have been extracted and all dosimetric param eters were compared between old and new protocol. The dose reduction for CT part of the MPI was approximately 52% for all the parameters analysed (CTDIvol, DLP, SSDE, Effective Dose) both for TD and SD protocol. The dose reduction for SPECT part was aligned with the reduction introduced in the new administered dose activity card. In MPI study we have achieved, with the new optimized protocol, a total dose reduction of about 30% in TD exams and of about 24% in SD exams (see table below). Using a software tool for monitoring and tracking radiation dose was possible to monitor, in real time, radiation exposure in SPECT/CT exams and analyze how to optimize the protocol to reduce effective dose to the patients.