This review paper aims to update and discuss the latest data available with respect to the effects of mushrooms in promoting the health and performance of broiler and layer chickens. Most studies proved that different preparations of mushrooms from diverse mushroom species improved feed utilization efficiency, growth rate, egg production, and quality traits. Mushroom supplementation decreased the count of pathogenic bacteria (
Clostridium spp.,
Coliforms, and
E.coli and increased that of beneficial ones (
Lactobacillus spp. and
Bifidobacterium) in both broiler and layer chickens. Inclusion of different preparations (powders, extracts, leftovers,
etc.) of mushrooms resulted in lower cholesterol and other lipid metabolites in poultry meat and eggs. Some studies reported no significant effect of mushroom on the performance of broiler and layer chickens, however, it is concluded that mushrooms, in various forms, could be included in poultry diets without any harmful effect on their health. Further research works are also suggested to investigate the opportunities for making mushrooms part of the compound poultry feed ingredients in countries like Ethiopia.