Comamonas testosteroni initially has been considered as a nonpathogenic microorganism until 1987; after which year, it has being recognized as a human pathogen with spectrum of infections both in adult and children. We report the first case of a healthy child who is 12 months old Omani girl presented with features of acute gastroenteritis with Comamonas testosteroni sepsis, that was treated successfully with two weeks course of intravenous ceftriaxone with excellent outcome. Most of the reported cases of Comamonas testosterone infection were sensitive to antibiotics with favorable outcome.