Volatile profile, aroma-active compounds and odor activity values of the shade-dried aerial parts of basil (Ocimum basilicum) were investigated. Basil samples used under the study were provided from Iran and Turkey. Volatile compounds were isolated using a purge and trap extraction system and analyzed by gas chromatography olfactometry. A total of 50 volatile compounds of which 29 originated from Iranian and 32 were of Turkish origin were determined. Terpenes were present at the overwhelmingly highest levels, followed by alcohols and aldehydes. Of the terpenes, methyl chavicol was the main compound of both samples. The aroma-active compounds of basils were investigated by using aroma extract dilution analysis (AEDA) for the first time. The application of AEDA revealed 18 aroma-active compounds, including terpenes (10), aldehydes (3), ketone (1), phenol (1), alcohol (1), and unknown compounds (2) were detected. Linalool and methyl chavicol had the greatest flavour dilution (FD) factors in both samples, amounting to 2048 and 1024, respectively.