The Mucorales are fungal microorganisms found in the environment, mostly in soil and organic decaying material. Humans have used these fungi for industrial production purposes, such as the fermentation of food or beverages. Nonetheless, these fungi can become opportunistic pathogens when encountering individuals with immunodeficiency. Environmental Mucorales can infect humans and animals through various pathways; once they have invaded the host, Mucorales display a set of virulence factors that enhance further dissemination from the infected tissue. In that regard, the host immune response plays an essential role in the resolution of the infection, especially for individuals with a higher risk of infection due to preexisting medical conditions, such as diabetes, hematological malignances, and organ transplantation. Current diagnosis of mucormycosis is based on the identification of the fungi in infected tissues, and actual treatments include administration of liposomal amphotericin B and itraconazole. However, as many other pathogenic fungi, Mucorales present resistance to antifungal agents. Owing to the worldwide relevance of Mucorales, we will resume in this chapter the trinity of environment, animals, and humans, along with beneficial and deleterious factors affecting human life.