This study was conducted in one of the central rift valley Lakes of Ethiopia, in LakernHawassa to assess the effect of commercial fishing activity on avian diversity andrnactivity patterns of Marabou Stork and African Fish-Eagle in the area. Commercialrnfishing site was selected as one study site and an area about 2 â€“ 3 km away from therncommercial fishing site area was selected as a non-fishing study site. The study wasrnconducted from July 2017 to March 2018 covering both wet and dry seasons. Datarncollection was carried out by careful and repeated observations in the selected studyrnsites. The result of the study showed that, the avian diversity in the commercialrnfishing site area of Lake Hawassa was less the avian diversity in the non-fishingrnsite of Lake Hawassa and it was significantly different between seasons ( P < 0.05 ).rnThe major diurnal activity of Marabou Stork in the commercial fishing site and nonfishingrnsite of Lake Hawassa during wet and dry seasons was foraging and it wasrnnot significantly different ( P > 0.05 ) between seasons and the between study sites.rnThe diurnal activity patterns of the African Fish-Eagle during both the wet and dryrnseasons in both study sites of Lake Hawassa had no significant difference ( P > 0.05rn). The study showed that, the commercial fishing activity in Lake Hawassa hadrnsignificant effect on the avian diversity ( P < 0.05 ). However, the commercial fishingrnactivity did not affect the diurnal activity patterns of the selected species of birds inrnLake Hawassa.