Most male cervids are more prone to dispersal, and disperse over greater distances than that covered by females. Milu (Père David's deer, Elaphurus davidianus) is a large cervid, endemic to China; it was extinct in the wild in the early 20th century, and was reintroduced to China in 1985. Several dozen Milu escaped from the fenced area of the Hubei Shishou Milu National Nature Reserve during the heavy flood of the Yangtze River in 1998, and formed naturally re-wild Milu populations in the Dongting Lake Region. It was unknown whether the re-wild male Milu are also prone to dispersal. We investigated the dispersal behavior of the naturally re-wild Milu in the Dongting Lake Region, China by monitoring populations from 1995 to 2012. Dispersal groups of Milu are classified as male, female, or mixed groups. We recorded 118 dispersal events, of which 26 were mixed groups, three were female groups, and six were male groups. For the recorded groups, we possessed accurate age structure and sex ratio records for 60 groups (23 mixed groups, 3 female groups, and 34 male groups). The results showed that dispersal frequency was higher in the male groups than in the female groups or the mixed groups. Fifty percent of the male dispersing groups contained a single, solitary stag. Dispersal distances in the male, female, and mixed groups were (13.73±8.74) km, (8.95±2.16) km, and (11.05±4.16) km, respectively. However, the three types of groups did not differ significantly in dispersal distances (χ² = 1.896, df= 2, P = 0.387). The dispersal distances of the female groups were < 15 km, but 89.28% of dispersals by mixed groups and 5.88% by male groups were >25 km. The three types of dispersal groups also differed in size. Mixed groups contained 26.39±15.97 individuals; female groups contained (2.33±1.15), and the male groups contained (2.74±2.86) individuals. The mixed groups were significantly larger than the female or the male groups (female: F = 48.085, df= 55, P < 0.05; male: F = 5.324, df= 24, P = 0.00 < 0.05), but the male and female groups did not differ significantly in size (F = 9.830, df= 35, P = 0.813). The male groups showed three dispersal peaks, in March, June, and November each year; the mixed groups showed four dispersal peaks, in January, March, July, and November; the female groups showed two dispersal peaks, in March and November. In conclusion, the male Milu is more prone to dispersal than the female. The dispersal ability of males is stronger than that of females, which may rely on males to disperse. The findings shed light on the management of naturally re-wild Milu populations.