Sierra Leone is a small, resource-limited country that has a low national prevalence of human immunodeficiency virus (HIV) and a very high burden of tuberculosis (TB). Fungal diseases are probably common, but poorly documented. In this article, we reviewed the existing literature on fungal epidemiology in Sierra Leone using national, regional, and international data, identified knowledge gaps, and propose solutions to address the challenges on the prevention and control of fungal diseases in Sierra Leone and similar countries. In advanced HIV disease, we estimate 300 cryptococcal meningitis, 640 Pneumocystis pneumonia, and over 4000 esophageal candidiasis cases annually. Chronic lung disease is common, with an estimated 6000 cases of chronic pulmonary aspergillosis, many mistaken for TB, 5000 adults with allergic bronchopulmonary aspergillosis complicating asthma, and probably over 6600 cases of severe asthma with fungal sensitization. Invasive aspergillosis is estimated at 478 cases. None of these diagnoses are made in Sierra Leone at present. Major burdens are recurrent vulvovaginal candidiasis (85,400) and tinea capitis in children (266,450). Improvement in fungal disease diagnosis in Sierra Leone will enable better estimates to be made and reduce morbidity and mortality.