In response to concerns raised by immigrant rights groups and complaints to the Office of Inspector General (OIG) Hotline about conditions for detainees held in U.S. Immigration and Customs Enforcement (ICE) custody, we conducted unannounced inspections of five detention facilities to evaluate their compliance with ICE detention standards. We identified problems that undermine the protection of detainees’ rights, their humane treatment, and the provision of a safe and healthy environment. Although the climate and detention conditions varied among the facilities and not every problem was present at all of them, our observations, interviews with detainees and staff, and our review of documents revealed several issues. Upon entering some facilities, detainees were housed incorrectly based on their criminal history. Further, in violation of standards, all detainees entering one facility were strip searched. Available language services were not always used to facilitate communication with detainees. Some facility staff reportedly deterred detainees from filing grievances and did not thoroughly document resolution of grievances. Staff did not always treat detainees respectfully and professionally, and some facilities may have misused segregation. Finally, we observed potentially unsafe and unhealthy detention conditions.