At Al Wabra Wildlife Preservation, mountain gazelles (Gazella gazella) have been kept very successfully. The Idmi (Gazella gazella) as well as the Yemeni gazelle (Gazella gazella cora) population grew constantly, whereas the mortality stayed almost on the same level or even decreased. In a retrospective study, causes of death were evaluated based on the necropsy reports from 227 Idmi and 82 Yemeni gazelles, which died during the period from 2001 to 2008. In both subspecies pneumonia, trauma and neglect were found as the main causes of death. Pneumonia occurred most often in juveniles. Most animals which died due to trauma were juveniles (77 %) in Idmi but adults (64 %) in Yemeni gazelles. Variations in mortality over the years reflected animal management.