Dragon-killer in national myths is an advocate that, with the help of god or deities for protecting people and making peace, does battle with the dragons. The dragon and dragon-killer have been represented with various signs in different cultures that are all the same, verbally and thematically and just differ from lingual aspects.Among from all versions of Dragon-killer myths around the world, we would concentrate on the Iranian and Indian ones throughout this research and especially would take myths of Bahram as an Iranian dragon-killer god and Indira as an Indian one, on one hand, and Iranian Fereydoun with Indian Rama, on the other hand, into comparative analysis consideration.The research method is based on library studies, in addition to Levi-Strauss’ structuralism theory.Moreover, according to Georges Dumezil’s theory, considering the Iranians and the Indians as a single race, we are to analyze the possible adaptation between Iranian and Indian myths, regarding Dragon-killer myths.This study shows the significant adaptations or similarities between Iranian and Indian dragon-killer myths, due to the general motifs of human mind or archetypes, on one hand, and the common cultural roots or background between those mentioned races, on the other hand. So, the common thematical aspects between Iranian and Indian myths regarding the dragon-killers stand beyond question. Moreover, the differences originate from the political, religious, social and geographical varieties through the passage of time.