In this project, the effectiveness of CaO as a disinfectant agent was evaluated in two substrates for the cultivation of orellana (Pleurotus ostreatus): sugar cane bagasse and pangola hay. For this purpose, the amounts of water and CaO effective in disinfection were evaluated. This was determined by evaluating the mycelial growth of orellana in the two substrates disinfected by this method. To five experimental units of 300 g tripled, different percentages of CaO were applied to each treatment taking as base the 52.64g of CaO and the 17% of humidity, determined by means of the theoretical calculation required at (100%, 75%, 50%, 25% and 0%), the experiment was repeated three times for hay and two times for cane bagasse. This experiment showed that a dose of 60% should be used for cane bagasse and 75% for hay, given its ability to inhibit the growth of unwanted microorganisms. However, the use of these CaO percentages resulted in an excess of Ca(OH)2 and a lack of H2O in the first sowing. Consequently, the substrates were saturated in a 3% CaO solution for both cane bagasse and hay (see Table 6). Finally, the disinfection of the two substrates used was achieved and the highest production occurred in this second trial, when hay was evaluated as a substrate. The result of this project opens an alternative for small artisanal producers with which the pasteurization and sterilization method currently used in the production of orellana can be substituted.