This research was conducted at AlTieba Research Station, General Commission for Scientific Agricultural Research (GCSAR) in 2012 and 2013 seasons, to study the effect of different doses of gamma rays on growth and productivity of local garlic Allium sativum L. cultivar “Yabroudi” in Syria. Cloves were exposed to four different doses of gamma rays of 60Co source 1, 2.5 ,5 ,10 ) Gray). Randomized Complete Block Design (RCBD) was used .The results showed the surviving plants after 60 days of planting declined with the increase of dose levels. The percentage of dead plants at the doses (2.5, 5 Gray) was 50 and 54 %, respectively. Also, it was possible to obtain a larger number of viable mutations. Therefore, they could be considered as close as to LD50. The dose (10 Gray) had a negative effect on the length of the cloves’ germination period, leading to the death of all the plants after 60 days of planting, this could be considered lethal dose (LD100). The response of the local garlic cultivar Yabroudi to the low-dose (1 Gray) of gamma ray was higher comparing with other doses. This is due to the positive effect of this dose (Stimulus) on the vegetative growth that was reflected on the productivity indicators. The productivity reached (4.50 kg/m2), which was significantly superior to the control (2.91 kg/ m2) and the two doses (2.5, 5 Gray), respectively (2.26, 1.60 kg/ m2).