Background: Pyelonephritis is a type of urinary tract infections (UTIs) that can cause severe systemic troublesome manifestations. Untreated cases of pyelonephritis can let the inflammation to damage the renal pelvis and its parenchyma. Also, an untreated infection may lead to sepsis, which can increase the rate of mortality. Objective: To review the published literature and provide an adequate review about evaluating and managing pyelonephritis properly. Method: PubMed database was used for article selection, and the following keys were used in the mesh ((“Pyelonephritis"[Mesh]) AND (“management” [Mesh]) OR (“evaluation"[Mesh])). Conclusion: The diagnosis of pyelonephritis should depend on clinical findings as well as laboratory values and imaging studies. Hydration and chosing the proper antibioticsare the mainstay of UTI treatment.