Background: Acute bacterial nephritis is an infectious process diagnosed through imaging studies. The clinical course of the disease has been shown to be more aggressive than acute pyelonephritis. It continues to be underdiagnosed, thus there are few studies on the entity in the literature. Objective: To describe the clinical characteristics and imaging features of acute bacterial nephritis, as well as its clinical course. Design: A descriptive, retrospective case series was conducted. Materials and methods: Thirty-two cases of acute bacterial nephritis in patients admitted to the hospital within the time frame of 2009 to 2016 were reviewed. The patients’ clinical characteristics upon admission were registered, as well as inpatient clinical progression, culture results, and antibiotic therapy response. The imaging studies were re-evaluated and the diagnostic consistency with either the focal or multifocal disease presentation was confirmed. Results: Cases predominated in women (n=29, 90.62%) and the most frequently associated comorbidities were diabetes (n=16, 50%) and obesity (n=9, 28.25%). The most important clinical findings upon admission were fever (n=15, 46.87%) and leukocytosis (n=27, 84.38%). Escherichia coli was the most commonly isolated bacterium (63.63%). Both acute focal bacterial nephritis and acute multifocal bacterial nephritis were observed in 46.87% (n=15) and 53.13% (n=17) of the patients, respectively. Imaging studies were required for all diagnoses. Conclusion: Fever and leukocytosis are the main findings in acute bacterial nephritis. Imaging studies are necessary for making the diagnosis, given that acute pyelonephritis and acute bacterial nephritis cannot be clinically differentiated.