Coprinus cinereus is a Tanzanian wild edible mushroom whose cultivation in the laboratory was performed in solid-state fermentation bioreactors using sisal decortication wastes namely; sisal dusts, sisal fibres and sisal leaves as basal substrates supplemented with chicken manure at various rates. Bioreactors containing 450 g wet weight of the three sisal wastes substrates each was supplemented with dry chicken manure at 0% (un-supplemented control), 5%, 10%, 15%, 20% and 25% of substrate dry weight. The effect of the test sisal waste substrates and chicken manure of various supplementation rates were evaluated by mushroom yield, (g fresh mushroom/kg moist substrate) and its biological efficiency, B.E. (relationship between fresh mushroom weight and dry substrate weight as percentage) and mushroom size (a ratio of total weight of fresh mushroom and total number of mushrooms). Each, sisal waste substrate and chicken manure supplement at various rates showed variable impact on mushroom yield, productivity and size. The overall best results of mushroom production were obtained in sisal dust at 25% chicken manure in terms of mushroom yield 381 g fresh mushrooms/kg moist substrate weight and its B.E. of 112% while mushroom size best results of 1.64 was obtained at 15% manure. In conclusion, results suggest that chicken manure from free-range chicken may play an important role on increasing the yield and productivity of Coprinus cinereus on sisal waste substrates under the conditions investigated.