Exposure to low-dose ionizing radiation has demonstrated to be associated with a certain risk of cancer but also non- cancer disease. However, only recent, high-quality, individual dosimetry data allowed this risk to be estimated. A correlation between low-dose exposures and various types of non-malignant diseases has only recently been suspected in Japanese atomic bomb survivors, liquidators of Chernobyl accident and various occupationally exposed cohorts and is still controversial. Data on excess relative risks per dose unit for moderate- and low-dose exposure from epidemiological studies are variable, possibly resulting from confounding factors and effectmodification by well known (but unobserved) risk factors. In the present work, we summarized the current evidence for a casual association between chronic, low-dose level radiation exposure and possible effects on embryo and fetus, heart and vessels and brain.