Objective: To study the effect of brucellosis infection during pregnancy on the rate of fetal loss and the possible role of antimicrobial therapy in modifying this effect.   Methods: A total number of 36 Jordanian pregnant women who presented with acute brucellosis during pregnancy in three hospitals over the period 1997-2003 were studied. The diagnosis of acute brucellosis was based on compatible clinical features and a serum agglutinin titer of ‰¥ 1: 320 or a positive blood culture result. The following information was collected: age of mother; obstetric history; gestational age at the time of infection; presenting symptoms; laboratory results including serological tests and blood culture for Brucella; antimicrobial therapy given and the fate of the fetus.   Results: The incidence of brucellosis was 0.5% per 1000 deliveries. 14 patients (38.9%) developed spontaneous miscarriage. One patient (2.8%) had Intrauterine Fetal Death (IUFD). Fetal loss was higher in patients with brucellosis during febrile episodes and in association with vaginal bleeding.   Conclusion: Acute brucellosis is associated with a higher than normal incidence of fetal loss rate, especially early in pregnancy, during febrile episodes and in association with vaginal bleeding. Early institution of antimicrobial therapy did not seem to influence the risk of fetal loss in our study.