Genetic diversity is one of principle factors to succeed in breeding programs, so its determination is vital in the using of plant genetic resources. With the aim of evaluation of genetic diversity among safflower landraces, 20 lines (14 Iranian and 6 foreign lines) were studied for phenotypic and genotypic variations using agro-morphological traits and RAPD markers. Field study was conducted in RCBD design with three replications in 2007-08. The results of analyses of variance showed that there was significant difference among the studied lines for all agro-morphological traits characters except number of heads. Plant height, number of head and seed germination had significantly positive correlation with grain yield. These traits also showed the most direct positive effects on yield and could explain 43% of total variation of grain yield. Out of 20 primers used in RAPD analysis, 12 primers were polymorphic and produced 104 clear polymorphic bands with average 8.7 band for each primer. Cluster analyses, based on both morphological traits and molecular data, classified the lines into four groups, however, there was not great similarities between two clusters (7.7%). It can be concluded that RAPD is a suitable technique to determine genetic diversity among studied safflower lines. The existence of the great genotypic variation among safflower landraces can be exploited in breeding programs in rainfed area of Iran.