OBJECTIVES: Injectable medications are common in the hospital setting and susceptible to errors that may harm patients. We conducted a descriptive analysis of injectable medication errors reported in the hospital setting in order to inform prevention efforts. METHODS: Year 2011 records documenting medication errors associated with injectable drugs were extracted from a national medication error reporting system representing ~1000 United States hospitals (Quantros Medmarx). Injectable medications were defined by administration routes “subcutaneous”, “intravenous”, “intramuscular”, or “epidural”. Records identifying inpatient and outpatient errors that reached the patient (National Coordinating Council Medication Error Reporting and Prevention Categories C-I) were analyzed.  For each record, staff type (discovered error), physical location, stage within the medication use process (prescribing, transcribing, dispensing, administering, monitoring, procuring) and error type were analyzed.   RESULTS: 5389 records identified injectable medication errors (4860 inpatient, 529 outpatient). Although seventeen different staff types discovered errors, 75% of records identified a nurse as discovering the error. Error locations most frequently reported were nursing units (59%), pharmacy (16%), ICU (10%), and emergency department (8%). The distribution of errors throughout the medication use process was: administering (57%), dispensing (20%), transcribing (12%), prescribing (8%), monitoring (2%) and procuring (1%). During administering, errors were most often typed as “omission error” (34%), “improper dose/quantity” (20%), “unauthorized / wrong drug” (10%), “wrong time” (9%), “wrong administration technique” (9%) and “extra dose” (8%). During dispensing (includes pharmacy preparation), errors were most often typed as “omission error” (25%), “improper dose/quantity” (20%), “wrong time” (17%) and “unauthorized / wrong drug” (10%). CONCLUSIONS: In 2011, the most frequent injectable medication errors were related to drug administering in nursing units and dose preparation and timing in pharmacy dispensing, with dose accuracy being a contributing factor in both locations.  Prevention efforts can be targeted on medication use processes and hospital locations where errors occur most often.