To cite this paper: ErtemVaizoğullar, H. and Y. Kara, 2016. AbstractThis study was carried out to investigate the physiological effects of gamma radiation on Jojoba (Simmondsia chinensis) Arizona A42 variety seeds. The seeds were irradiated with doses of 0 (control), 100, 200, 300, 400 and 500 Gy gamma radiation using cesium (Cs 137 ) source. After irradiation; crude oil yield, antimicrobial activity and chemical composition were determined. Extraction of the seeds was done with soxhlet apparatus using petroleum ether. The result showed that the highest crude oil yield was obtained from 500 Gy. Compared to reference antibiotics, seed extracts applied with 500 Gy of the S.chinensis-Arizona A42 had a strong antibacterial activities against the Escherichia coli ATCC 25922 and P. aeruginosa ATCC 27853. Gamma radiation had no significant effect on oil composition of S. chinensis-Arizona A42 seed extracts. The chemical composition of the all extracts elucidated presence of average in major oleic acid (65%) and linoliec acid (15%) at 500 Gy, respectively.