In this report we present a case of a young lady with abdominal abscesses and septicemia caused by Mycobacterium chelonae complex. Identification of the organism and initiation of the appropriate antimicrobial therapy was delayed, resulting in significant morbidity and multiple hospital admissions. Gram staining of these organisms from blood culture can be easily overlooked or confused with either debris or diptheroids. We concluded that detection of Gram-positive rod colonies should prompt an acid-fast stain to distinguish diphtheroids from rapidly growing mycobacteria in immunosuppressed patients.