The Arabian oryx (Oryx leucoryx) is an endangered ungulate that became extinct in the wild in 1972, but conservation plans are underway to save this species. This includes a program in Oman involving captive breeding for reintroduction into the wild using a few captive populations from around the world. However, there is limited knowledge of the actual genetic diversity of the breeding populations from Oman. As a first step to address this, we investigate the mitochondrial DNA (mtDNA) of 114 individuals from three groups held at the Omani Al Wusta Wildlife Reserve (originally from Oman; sourced from the United Arab Emirates; and a mixed group which are the result of preliminary breeding between the former two groups) as well as 24 historical samples from private collections. We identified 9 haplotypes out of the 18 previously identified globally in the Arabian oryx founder population for the Omani conservation initiative. The results indicate that genetic variability among the three groups held in this reserve is slightly below the observed average found in other Arabian oryx populations. Our findings improve knowledge of the current status of the genetic diversity of the oryx and support the future strategy of translocation and genetic management of reintroduced populations. This data provides a preliminary tool to inform the management of this conservation program allowing adequate selection of breeding pairs to preserve mtDNA variability. Population genomic analyses using dd-RAD sequencing are underway to better understand the genetic make-up of the Arabian oryx.