Acute lobar nephronia is an uncommon type of urinary tract infection affecting the kidneys and more commonly reported in the pediatrics population. It can be a precursor to renal abscess formation if undertreated. Escherichia coli is the commonest pathogen observed in adults with this condition but other organisms have also been reported. This case report describes a 65-year-old woman whose work-up for fever, nausea and vomiting led to the diagnosis of acute lobar nephronia caused by Enterobacter cloacae. The acute lobar nephronia was identified on ultrasound of the kidneys. She was successfully treated with intravenous gentamicin followed by oral ciprofloxacin. Repeat ultrasound showed resolution of the nephronia. This case highlights the need for clinicians to be aware of this condition and ensure appropriate antibiotic treatment to prevent progression into a renal abscess.