Encompassing most relevant works that have appeared to date, this article examines and evaluates as objectively as possible various old and new hypotheses regarding the genetic affiliation of Japanese and Korean. The first part of the article (sections 1-6) concerns the works that relate the two languages to Altaic or Austronesian, touching briefly on the Tamil substratum hypothesis at the end. It is observed that the Altaic hypothesis is the most persuasive in view of the data presently available. The second part (sections 7-8) reviews the works dealing with the relationship between Japanese and Korean. It appears undeniable that the two languages are genetically related sister languages. The article closes with some brief suggestions for future research.