The gram-positive bacterium Gemella morbillorum has been recovered from patients with endocarditis but has rarely been associated with acute fulminant infections. We describe two children with a rapid onset of septic shock, which was fatal in one, following infection with this organism. G. morbillorum is a commensal organism of the upper respiratory tract; it gained access to the bloodstreams in these patients, and bacteremia occurred. A clinical drawback is that the initial colonial morphology of this organism leads to presumptive identification as a viridans streptococcus, an organism not commonly associated with septic shock syndrome. Resistance of G. morbillorum to penicillin appears to be common; therefore, initial empirical combination therapy (a beta-lactam agent and an aminoglycoside) or vancomycin treatment should be considered.