Three experiments were conducted to investigate the effects of drinking water supplementation with 0, 5 and 10 ppm of Nano-silver particles (AgNPs) / liter  on performance, carcass characteristics and gut micro-flora population of grower rabbits from 63 to 91day of age,  broiler chicks from 1 to 42 day of age and grower Japanese quails from 7 to 42 days of age. Results showed that, different levels of AgNPs in drinking water hadn't any significant effect on body weight, body weight gain (BWG) or feed conversion ratio (FCR) of rabbits. Concerning broiler chicks; the control group performed well compared with supplemented groups. Both BWG and FCR for Japanese quails recorded best values for 10 ppm supplemented group compared with control group. In all tested poultry species, the levels of 5 ppm and 10 ppm resulted in a reduction in total viable bacteria, pathogenic bacteria representing E Coli and beneficial bacteria representing Lactobacillus of intestinal gut especially for 10 ppm level causing negative effect on performance of grower broiler chicks but less on grower rabbits or Japanese quail, suggesting that, both species may be less sensitive for existence of AgNPs in drinking water, while broiler chicks might be more sensitive. Most of carcass characteristics were not significantly affected by existence or level of drinking water AgNPs supplementation except liver percent of grower quail, which needs to undergo more research works.