Cancer breast is one of the leading causes of death and it is the commonest cause of women death by cancer, its prevention remains a challenge, thus early and accurate diagnosis are mandatory to achieve this target. This work is aiming for a comparison between sensitivity and specificity of CT alone versus those of PET/CT in post-surgical follow up of patients with breast cancer. This study was conducted on (31) female patients from 2015 to 2019. Their ages ranged from 25 to73 years with mean age of 51 years All patients have positive history of breast cancer surgery. Those patients were referred to Misr Radiology Center, Cairo for post-operative follow up by PET/CT. FDG-PET-CT is very useful in evaluating the response after therapy. The technique also can detect response to therapy very early before any other available imaging modality. PET-CT is helpful in evaluating regions treated with chemotherapy or radiotherapy and differentiating between recurrence and post treatment changes.