This article reports the largest nosocomial outbreak of B. cepacia-related Hospital Acquired Infectios (HAIs) and the epidemiological investigations leading to identification of ultrasound gel as a direct means of infection transmission. Multiple environmental sampling was conducted to identify the source and route of infection. The samples were collected from all sources considered to be potential reservoirs of B. cepacia. Standard methods for pathogen isolation and antibiotic sensitivity testing were used. In all, 61 patients developed B. cepacia-related sepsis and this agent was isolated only from ultrasonography gel. All patients required the placement of a central venous line to receive the chemotherapy for the underlying hematologic disease. The hospital outbreak persisted after identification of the source of infection and it took more than four months to be completely eradicated after the first cases. B. cepacia is a serious threat for hospitalized patients needing invasive procedures, including the central line placement for chemotherapy, regardless of the need of any intensive care. Implementation of protocols for active surveillance of HAIs should also target this opportunistic agent and include periodic sterility control of commonly used medical materials, including ultrasonography gel and equipment.