Abstract Introduction: A type of disease where a small percentage of the population has been affected are called rare diseases. The rare diseases subject is full of misunderstandings. The goal of our study was to study the epidemiological properties of Rare Diseases by identifying and reviewing relevant qualitative literature on prevalence and mortality of Rare Diseases in an attempt to demystify the subject. Methods: All Published articles were searched from PubMed using the combination of keywords for studies published from 2000 to 2020. Initially, all the citations were imported to EndNote Version 20. The duplicates were removed. Eligible articles were stored in Microsoft Excel Spreadsheet. Results: Among 2962 identified articles, 24 studies were included in the study from 13 countries, Europe, Asia, United States of America, and Africa. Overall, from the study we summarized that Asia Continent has more prevalence and mortality due to rare diseases than Europe, USA, and Africa. We also found that countries having high income shows a low prevalence and mortality of rare diseases as compared to countries having low income. Conclusion: There is a considerable burden of rare disease in terms of morbidity and mortality as well as disability irrespective of the gender, and geographic location. Although there are coding systems for rare diseases, but the mortality caused by Rare Diseases is not well known and low income developing countries have scarce literature. Therefore, future studies are warned to track progress and healthcare needs of people with rare disease to fulfill our commitments to the “Health for all”.