- Ertapenem is being increasingly utilized in cancer patients, but published data regarding its usage are limited. Our objective was to describe the various indications for ertapenem therapy and its safety and efficacy in cancer patients. We conducted a retrospective cohort study of cancer patients who received monotherapy with ertapenem for at least 72 h, between January 2007 and February 2013. Among 97 unique patients who received ertapenem monotherapy, the most common indications were: (1) To facilitate discharge from the hospital of stable patients still requiring antimicrobial therapy (46 %). (2) Primary therapy of various documented infections (bacteremia, pneumonia, urinary tract infection, skin and skin structure infection) with ertapenem (28 %). (3) De-escalation from a different broad-spectrum agent or regimen to ertapenem within the hospital setting in patients not ready for discharge (25 %). The median age of the 97 patients studied was 59 years (range 9-87 years) with 52 % being men. Most patients had underlying hematologic malignancies (54 %), and 7 % were recipients of hematopoietic stem cell transplantation. Twenty-nine patients (30 %) were neutropenic, 26 % were diabetic, and 6 % had chronic lung disease. Primary ertapenem monotherapy was successful in all patients, de-escalation in 95.8 % of patients, and the strategy of discharge on outpatient therapy with ertapenem in 95.6 % of patients. Patients failing de-escalation or early discharge responded to alternative regimens. We documented no significant ertapenem associated toxicity or adverse events. Ertapenem appears to be safe and effective for several indications in cancer patients.