Genetic diversity of 12 castor bean accessions collected from different geographical regions of Iran was assessed in a randomized complete block design with three replications under filed condition. The data were recorded for 32 agro-morphological traits. Significant differences were observed among accessions for main stem length, main stem moist weight, main stem dry weight, 10-seeds weight on primary raceme, seed number on primary raceme, leaf area dry weight, female flower length, male flower length, secondary and tertiary raceme weight and oil percentage. A strongly positive correlation was observed between total seed weight on primary raceme as yield with seed number on primary raceme, female flower length, primary raceme length and main stem diameter. Path coefficient analysis indicated high direct effect of seed number on primary raceme (0.82) on seed yield. In addition, direct effect of primary raceme length on seed yield was negative (-0.13). Primary raceme length had the greatest indirect effect via seed number on seed yield (0.35).