Urinary tract infection is very common and in most cases is self limiting even without treatment. However, in some cases, the infection may progress and leads to serious complication requiring admission and treatment. Emphysematous pyelonephritis is a rare but serious complication of urinary tract infection. The symptoms are similar to those seen in pyelonephritis and without radiological imaging; the diagnosis can be missed with serious consequence. In severe cases, nephrectomy may be indicated. We report a case of emphysematous pyelonephritis in a previously well obese 28 year old lady who was successfully managed with intravenous antibiotic. Her underlying risk factor was undiagnosed diabetes mellitus.