The study describes two successfully treated case reports of acute invasive fungal rhinosinusitis caused by fungi of the genus Mucor, where the patients received isavuconazole before and after surgery and had a good outcome. At the same time, the authors retrospectively analyzed 387 cases of Mucor and Aspergillus infections published for the years 2011–2025. The average age of patients with Mucor infection was 41 ± 31.11 years and with Aspergillus 32.5 ± 29.99 years. The efficacy of isavuconazole monotherapy was 89.47%, which was statistically significantly higher than amphotericin B monotherapy (59.68%, p < 0.05). Combined treatment with isavuconazole had an efficacy of 86.67%, also significantly higher than amphotericin B monotherapy (p < 0.05). Combined treatment with amphotericin B had an efficacy of 76.92%, marginally better than amphotericin B monotherapy (59.68%, p < 0.05). In conclusion, the authors report that the efficacy of isavuconazole in the treatment of invasive aspergillosis and mucormycosis significantly exceeds the efficacy of amphotericin B and is comparable to voriconazole (p < 0.05), which may help in the choice of treatment.