Knowledge on species diversity, distribution and abundance are among prerequisite ecological information to design sound conservation strategy. The present study was carried out to assess diversity, distribution and relative abundance of avian fauna in Dhati Walel National Park, western Ethiopia. Data were collected from June 2013 to May 2014 from three habitat types: wetland, woodland, and riverine forest. Data were collected using the method of line transects in wetland and woodland and point count method in riverine forest. A total of 124 avian species belonging to 18 orders and 50 families were recorded during the whole study period. Twenty-three families were from order Passeriformes. Three species: Banded barbet (Lybius undatus), Erlanger’s lark (Calandrella erlangeri) and Wattled ibis (Bostrychia carunculata), are endemic to Ethiopia and Eritrea. The highest number of species (14) was recorded from the family Accipitridae (order Accipitriformes). Families Columbidae (order Columbiformes), Nectariniidae (order Passeriformes) and Ciconiidae (order Charadriiformes) were represented with nine, six and five species, respectively. Woodland supported the highest avian diversity both during wet (H’ = 3.96) and dry (H’= 3.71) seasons.  Wetland was the least diversified (H’= 2.93, wet and H’ = 3.07, dry) in both seasons. Similarity of bird species was more between woodland and riverine forest both during the wet (SI=0.44) and dry (SI=0.31) seasons. There were no rare species and many frequent (33 species wet and 38 species dry seasons) and common (23 wet) species were recorded in the woodland. Awareness creation to reduce human pressure and research on the remaining habitat of the park are recommended.