Frost tolerant safflower genotypes (Carthamous tinctorius L.) could be used as winter crop to increase oil production under cold dryland conditions. To prove national safflower capacity for harsh winter survival, 56 accessions of local safflower were evaluated under controlled and field conditions in the northwest of Iran from 2008 to 2010. In the first year, accessions were tested for their capability to withstand remaining frozen for various freezing temperatures and different time. Survival of fully acclimated seedlings was evaluated after remaining frozen for 12 hours to 20 hours at -3 degrees C which continuously decreased -2 in each hour up to -19 degrees C. There was a large variability among accessions for freezing tolerance expressed as the lethal temperature for 50% of the plants (LT50) with temperatures ranging from -3 to -19 degrees C. Variation was observed between genotypes originating from the same province and even the same region. Survival after 12 hours at -3 degrees C ranged from 0 to 100% and after 20 hours ranged from 0 to 20%. In the second year, there was a large variation among the accessions for plant establishment (2-88%) in the field during spring 2010. The rankings of the accessions based on survival after natural winter cold during 2009-2010 was highly correlated with the rankings after LT50 testing under controlled conditions. Eleven accessions were identified as cold tolerant based on the results of both LT50 scores and field evaluation under cold dryland conditions.