In our study, we aimed to compare the Rose Bengal test (RBT), Coombs gel test (CGT), enzyme-linked immunosorbent assay (ELISA), and blood culture used in brucellosis patients in the light of acute phase reactants (white blood cell count (WBC), sedimentation, C-reactive protein (CRP)), inflammatory parameters (neutrophil–lymphocyte ratio (NLR), platelet–lymphocyte ratio (PLR), systemic immune-inflammation index (SII), systemic inflammation response index (SIRI)), and biochemical parameters, and to determine the impact of this comparison on clinical practice. Here, CRP is linked to brucellosis.