This study was carried out to determine the associated factors and the reasons for inappropriate utilisation of Emergency Department (ED) services at Universiti Sains Malaysia Hospital. A case control study was conducted with 170 cases from ED and 170 controls from the Outpatient Department (OPD). A self-administered questionnaire was designed and used to obtain sociodemographic data, knowledge on the functions of ED and OPD, health seeking attitude and behaviour, and reasons for seeking treatment at ED. The study found that gender, marital status, family size, shift work, perceived illness, and knowledge on the role and functions of ED and OPD were significant associated factors. The three most common reasons for inappropriate utilisation of ED were as follows: “due to severity of illness” (85%), “can’t go to OPD during office hours” (42%), and “ED near my house” (27%). Asia Pac J Public Health 2007; 19(2): 29–36.

Keywords: Emergency department, inappropriate utilisation, OPD services, perceived illness, university hospital