Food enrichment with minerals has been a method of increasing health benefits. Edible Pleurotus ostreatus mushrooms are a source of dietary elements and antioxidants. In this work, the phenolic content, antioxidant activity and metal content of P. ostreatus grown on coffee husk, enriched with iron (Fe), zinc (Zn) and lithium (Li) were investigated. The content of phenolic compounds was found to be different in mushroom enriched with Fe, Zn or Li. In DPPH test, a difference was observed in antioxidant activity; however, no difference in this activity was observed using β-carotene/linoleic acid test. The enrichment with minerals promoted decrease in the content of Fe in three enriched samples. There was no change in the content of Zn in the samples. Observed the accumulation of Li in the sample enriched with LiCl and P. ostreatus enriched with Fe, Zn or Li provided minerals such as K, P, Fe, Zn, Li and Cu. In addition, no heavy metals such as Ni, Cr and Cd were detected, and only low levels of Pb and Al were observed. The study was the first report to demonstrate the understanding of how mineral supplementation reduces antioxidant activity in P. ostreatus enriched with iron, zinc or lithium.