Introduction: Enterobacteriaceae are a group of gram-negative rods that can cause serious infections in humans. A susceptibility in Klebsiella pneumoniae of 79.4% to piperacillin/tazobactam (PIP/TAZO) is reported in pediatric hospitals in Chile. There is no published data published to date regarding PIP/TAZO susceptibility to other Enterobacteriaceae species in this population. Aim: To measure the in vitro PIP/TAZO susceptibility in Enterobacteriaceae isolates from patients in a pediatric hospital in Chile. Methods: Descriptive and prospective study of Enterobacteriaceae positive cultures from patients assisting to the "Hospital de ninos Roberto del Rio" (HRRIO) between January 2013 and August 2014. PIP/TAZO susceptibility was established by gradient diffusion method (E-test (R)) according to the 2014 CLSI standards. Results: 163 cases were included. The average age was 4 years and 15 days. 70.6% were female. 79.7% of samples were urine cultures. PIP/TAZO susceptibility in Enterobacteriaceae was 95.1% (n = 155). The intermediate susceptibility was 1.8% (n = 3). Discussion: The isolates studied present high susceptibility to PIP/TAZO. This finding could be explained by the fact that this population has not been exposed to this antimicrobial therapy and also the low rates for ESBL in pediatric infections.