Etymology of the words in different Iranian dialects helps not only to better understand their phonology, but also it helps to the etymology of Persian and other Iranian languages and dialects. Iranian dialects are a rich source of linguistic data which could be used in the linguistics of Iranian languages. This paper deals with etymology of 12 archaic words from diverse Iranian dialects. For each word, after investigating the same word or its cognates in the other Iranian dialects and languages, its Old Iranian form has been reconstructed and its sound changes from Old Iranian up to Iranian dialects have been examined. The list of words examined in this paper are as follows: arde / âla »side, half«, hast / ast» house, yard«, daha»awn«, bīg / gwask »goat, calf«, gūn »udder«, jeven »grain mortar«, jəxūn »threshing-floor«, kahra »goat, kid«, kətū »dog«, mâl »cattle, quadrupeds«, tâta »uncle«, xal »bent, crooked«.