Background and objectives: Medical waste management is a major concern forhealthcare facilities. One important element is the segregation of infectious wastefrom domestic, non-infectious waste. The aim of this qualitative study was to iden-tify factors that negatively affect proper segregation at Nemazee Hospital, which isaffiliated with Shiraz University of Medical Sciences.Methods: Study data came from focus groups involving hospital workers. Partici-pants expressed their opinions regarding barriers to proper segregation of medicalwastes. The participants gave their permission to have their comments recorded.Data analyses were based on a grounded theory approach.Results: The results indicated that managerial weakness was an important factor insuboptimal disposal of medical waste. It appears that hospital authorities should paybetter attention to educational planning, organizational resources and supervision.Together, these considerations should help reduce waste-management errors. Theresults also suggest that healthcare worker training needs improvement. In general,patients and their companions, as well as the local population, did not appear tohave sufficient knowledge concerning disposal of infectious medical waste.