In this study, we investigated the geriatric patients admitted to our clinic with the diagnosis of UTI and evaluated the effects of white blood cell (WBC), neutrophil count, platelet, MPV, RDW, total bilirubin, direct bilirubin, creatine, albumin, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and neutrophil/ lymphocyte ratio parameters on estimating the need for bacteremia and intensive care (IC) for the patients with pyelonephritis. Here, CRP is linked to bacterial urinary tract infection.