Zolpidem (trade name Ambien ®) is commonly prescribed. Case reports and popular media suggest potential dangers exist and may result in unanticipated complications. The primary aim was to determine how commonly zolpidem ingestion results in hospital evaluation and admission. The secondary aim of this study was to determine what patient and clinical characteristics are associated with complications from zolpidem use. A retrospective review of all cases involving zolpidem reported to the Illinois Poison Center between January 1, 2004 and December 31, 2005 was conducted. Data were prospectively entered into a structured clinical database in real time at the Illinois Poison Center. Demographic, co-ingestant, and outcome data for all zolpidem cases was abstracted into a research database and analyzed using descriptive, univariate and multivariate analyses. Six-hundred ninety-two cases met inclusion criteria. Mean age was 34.7 years. Four-hundred sixty three cases (67%) resulted in Emergency Department (ED) evaluation. Only 17% (81/463) of ED patients were discharged home: 44% (203/463) required Intensive Care Unit (ICU) admit, 17% (79/463) medical floor admit, 16% (72/463) psychiatry admit. Associated with ICU admission were co-ingestion of over-the-counter medicines (OR 3.33, 95% CI, 1.93 to 5.76), other prescribed psychotropics (antidepressants or mood stabilizers) (OR 3.11, 95% CI, 2.21 to 4.39), or ethanol (OR 2.12, 95% CI, 1.36 to 3.32). When zolpidem is ingested with other medications or ethanol, admission to the ICU was common in our series. Despite its reported safely, zolpidem overdose often requires ICU admission from the ED, which is associated with ingestion of other pharmaceutical products or alcohol.