BACKGROUND: Few studies have examined the impact of inpatient interpreter use for limited English proficient (LEP) patients on length of stay (LOS), 30-day post discharge emergency department (ED) visits and 30-day hospital readmission rates for LEP patients. METHODS: A retrospective cohort analysis was conducted of all hospitalized patients admitted to the general medicine service at a large academic center. For patients self-reported as LEP, use of interpreters during each episode of hospitalization was categorized as: 1) interpreter used by non-MD (i.e., nurse); 2) interpreter used by a nonHospitalist MD; 3) interpreter used by Hospitalist; and 4) no interpreter used during hospitalization. We examined the association of English proficiency and interpreter use on outcomes utilizing Poisson and logistic regression models. RESULTS: Of 4,224 patients, 564 (13 %) were LEP. Of these LEP patients, 65.8 % never had a documented interpreter visit, 16.8 % utilized an interpreter with a non-MD, 12.6 % utilized an interpreter with a nonHospitalist MD and 4.8 % utilized an interpreter with a hospitalist present. In adjusted models, compared to English speakers, LEP patients with no interpreters had significantly shorter LOS. There were no differences in readmission rates and ED utilization between LEP and English-speaking patients. Compared to LEP patients with no interpreter use, those who had a physician use an interpreter had odds for a longer LOS, but there was no difference in odds of readmission or ED utilization. CONCLUSION: Academic hospital clinician use of interpreters remains highly variable and physicians may selectively be using interpreters for the sickest patients.KEY WORDS: limited English proficiency; interpreter use; length of stay; thirty-day readmissions.