Selenium has several physiological functions in protein activity, enhancing immune system function, reducing cancer risk (Finley, 2006), collateral effects of chemotherapy (Sieja & Talercszyk, 2004) and functional activity of cancer metastasis (Finley, Sigrid-Keck, Robbins, & Hintze, 2005). Thus, the aim of this work was to evaluate the use of coffee husk in the production of Pleurotus ostreatus mushrooms enriched with selenium.