Despite stable genomes of all living organisms, they are subject to damage by chemical and physical agents in the environment (e.g., UV and ionizing radiations, chemical mutagens, fungal and bacterial toxins, etc.) and by free radicals or alkylating agents endogenously generated in metabolism. DNA is also damaged because of errors during its replication. The DNA lesions produced by these damaging agents could be due to altered base, missing base, mismatch base, linked pyrimidines, deletion or insertion strand breaks, intra- and inter-strand cross-linksExcessive reactive oxygen species may cause irreparable DNA damage, leading to mutagenesis and perhaps cancer. Investigation into the nature of DNA damage and repair have provided valuable insight into aging, human genetics and cancer. Now, there is deep interest in identifying free radical scavengers or antioxidants that inhibit oxidative DNA damage. This review describes all the possible mechanisms of DNA damage and repair in general and recent progress in plants.