Objective. To evaluate the efficacy and safety of intravenous (IV) fluid and diazepam therapy compared with the IV-fluid only therapy for the resistant hyperemesis gravidarum (HG) cases. Methods. Medical records of 74 HG cases who were refractory to standard management were reviewed. All patients hospitalised were administered IV fluid and multivitamin combination as the first-step therapy. Patients who were refractory to first-step therapy were given IV fluid (Group 1, n=43) or IV fluid and diazepam (Group 2, n=31) depending on the patients' desire. Groups were matched for demographic characteristics, rehospitalisation requirement, patient satisfaction and neonatal outcomes. Results. Thirteen of the 74 patients were excluded from the study because of unknown maternal and fetal outcome. The mean gestational age was 10.42.4 year. Age, parity, body mass index and educational level were similar between the two groups. Mean diazepam dose was 62.824.5mg (range 40-160) in Group 2 (n=31). The number of hospitalisation was significantly lower, and patient satisfaction was significantly higher in Group 2. There were no differences for the obstetrics outcomes between the groups. Conclusions. The addition of diazepam to IV fluids was associated with less hospitalisation in women with hyperemesis gravidarum. Safety of diazepam therapy in early pregnancy deserves further study.