Adenovirus can produce severe disease and even death in the immunocompromised neonate. Symptoms of adenovirus infection are similar to those seen with bacterial infections in neonates, making early recognition and diagnosis difficult. Consideration of adenovirus as a causative agent is important to early diagnosis. Currently available culture techniques, particularly the shell vial culture technique, make more rapid identification of adenovirus infection possible. Early identification and treatment are necessary to improve patient outcomes and prevent the spread of infection to other neonates. Available agents for the treatment of adenovirus have had mixed results, yet their use is preferable to nontreatment of critical patients. This article presents the case of a preterm infant who became fatally ill from disseminated adenoviral infection.