The aim of the present study is to evaluate the relationship between the immunohistochemical and histopathological prognostic factors and the metabolic fluorine-18 fluorodeoxyglucose positron emission tomography/computerized tomography (PET/CT) parameters in breast cancer. A total of 94 female patients diagnosed with primary breast cancer (median age: 54.5 years, 94 lesions with size >15mm) who underwent PET/CT imaging before any treatment were enrolled to this retrospective study. Maximum and average standardized uptake values (SUVmax and SUVavg), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and tumor/liver uptake ratio (TLR) of the primary tumors were calculated and compared between various histopathological and immunohistochemical prognostic factor groups. All metabolic parameters were associated with clinical T stage, metabolic M stage, and nuclear grade. The MTV, TLG, and TLR were significantly higher in patients with suspected lymph node metastasis. There were significant differences according to estrogen receptor and human epidermal growth factor-2 status in the metabolic values other than MTV. In case of progesterone receptor, there were significant differences in the metabolic characteristics except for the MTV and TLG values. The Ki-67 labeling index was moderately correlated with SUVmax, SUVavg, and TLR. All metabolic characteristics except MTV were significantly higher in triple negative breast cancer compared with the other molecular subtypes. The results of the present study suggest that the TLG and TLR values have stronger associations with several prognostic factors in breast cancer (BC) compared with other metabolic parameters.