Background: Kelussia odoratissima Mozaff. from Apiaceae family is a perennial herbaceous plant endemic to the west of Iran. The aromatic aerial parts of this species are traditionally used by indigenous people to flavor some local foods, as well as for various therapeutic purposes. Objective: The present study was designed to analyze phenolic compounds and essential oil constituents of K. odoratissima fruits. Methods: The n-butanol fraction obtained from hydroalcoholic extract of K. odoratissima fruits was investigated by chromatography on normal phase and Sephadex LH-20 columns. Chemical structures of the isolated compounds were clarified by ¹ H-NMR and ¹ ³ C-NMR spectral analyses. Essential oil constituents of the fruits were also analyzed using GC-MS. Results: Phytochemical investigation of the K. odoratissima fruits resulted in the isolation of five flavonol glycosides; isorhamnetin 3-O-glucoside (1), quercetin 3-O-glucoside (isoquercetin) (2), isorhamnetin 3-O-rutinoside (narcissin) (3), isorhamnetin 3-O-glucuronide (4) and quercetin 3-O-glucuronide (mequilianin) (5). GC-MS analysis of the fruits essential oil led to the identification of the thirty six compounds, of which (Z)-ligustilide (15. 93 %), δ-cadinene (12. 26 %) and germacrene D (12. 18 %) were the main compounds. Conclusion: The results of this study introduce K. odoratissima fruits as a source of flavonoid glycosides and phthalate derivatives. The presence of these compounds with known biological properties and health beneficial effects provides more medicinal potentials for the fruits of K. odoratissima and suggest it an appropriate option for further studies.