The Persian wild ass (Equushemionusonager) has the smallest population among various wild ass subspecies and has only two isolated populations (500-600 individuals), that has been left in Iran. Therefore, captive breeding and re-introduction with post-release monitoring is considered a reliable conservation action. The present investigation illustrates efforts to re-introduce the onagers to its historical range in the Kalmand-Bahadoran protected area and presents monitoring efforts within the first two years of the scheme. Accordingly, a total of 12 onagers including 5 males, 6 females and one foal were released from Tang Hanna enclosure to Kalmand which have been trans-located from the GourabOnager Breeding site to the release site. Short- term post-release monitoring was undertaken between July 2010 and July 2012 by means of direct observation. The social structure of released onagers did not facilitate contribution of all stallions in breeding, resulting in a smaller effective population size during the monitoring phase comparing to its actual number. Maternal herd occurred in an area of 20820/9 hectares in contrast to a solitary stallion roamed within a convex of 5941/7 hectares. Intra-sexual competition encouraged the stallions to disperse longer than females which made them more susceptible to a variety of threats and even one adult stallion died during dispersal. Due to the small number of founder population, its growth rate is low which necessitates releasing a few females and at least one stallion from other onager populations in the country to motivate population increase and to prevent probable inbreeding depression.