Studies were carried out on bacteria which usually infect spawns and culture plates of Psathyrella atroumbonata (Pegler) and Schizophyllum commune (Fr. ex. Fr.), two Nigerian edible mushrooms. During the vegetative propagation of these higher fungi, six different bacterial species were isolated and characterized from 14-day-old spawns and mycelial ramified PDA culture plates. These bacteria include Bacillus licheniformis, Bacillus subtilis, Leuconostoc mesenteroides, Pseudomonas aeruginosa, Bacillus cereus and Staphylococcus aureus. The average bacteria count was 1.0 x 106 cfu/ml and these bacteria grew within pH range of 5.0 and 9.0. The optimum temperature range of growth is between 30 °C and 37 °C. The significance of these findings to the cultivation of P. atroumbonata and S. commune in Nigeria was discussed.