Background/Objectives: The main objective of the present study is to find a relationship between radon exposure and the incidence of some malignant or non-malignant diseases. Methods: To find risks of occurrence of some diseases associated with radon exposure, this study reviewed published literature reporting the sources of radon, indoor and outdoor radon entry, factors influencing the radon concentrations, and induced health effects associated with radon and its decay products. Findings: Health hazards caused by radon (222Rn) exposure are mainly due to its decay radionuclides of 218Po, 214Po and 210Po. A high-level radon exposure is a risk factor for lung cancer. It is strongly associated with risks of some cancer in blood, skin, stomach and brain. The link of malignancies in the cardiovascular system, kidney and pancreas with radon exposures is controversial, but cannot be ruled out for the kidney. Radon has a significant effect on the reproductive system and growth of offspring at different gestation periods of women. Radon may also account for some other diseases, including COPD in lungs, diseases in esophageal, and rectum, or colorectal of the digestive system, cancers in the lip, oral cavity, and also pharynx and laryngeal cancers. Radon-induced diseases including cancers are susceptible to race, gender, or children, particularly cancers or diseases in lungs, stomach, brain, pancreas, female breast, and fetus. More systematic studies are required to find a correlation of radon exposure with malignant and non-malignant diseases. The vulnerable population for such exposure (miners and dwellers of colder regions) needs to be identified for protective measures. Of course, the contribution of Radon to the possible background radiation exposure, which may attribute to the hormetic effect, is almost outside the scope of the present study. Novelty/Applications: Present study provides some valuable information regarding evidence of some health effects caused by radon and its decay products. This can help researchers and the general population. Keywords: Radon; health effects; cancer; mortality; miners; general population