The knowledge of geometrical properties such as shape and size is essential for the design of processing equipment including separating, handling, sizing, drying and dehulling. In this research, geometrical properties of three varieties of Iranian oil and confectionary sunflower seed and its kernel (Shahroodi, Fandoghi and Azargol known as confectionary, semi-oil and oil varieties respectively) were investigated as a function of size and variety in the range of moisture contents from 3% to 14% (d.b.). The range of seed length for Fandoghi, Azargol and Shahroodi varieties at 7 %(d.b) were 11.03 - 12.10, 13.79 -15.13 and 13.31-14.54 mm, respectively. Moreover, these values for the corresponding kernels at 7 %(d.b) were 8.75 - 9.22, 10.48 - 10.96 and 10.67- 11.45 mm, respectively. The results showed that all main dimensions (length, width and thickness), sphericity, surface area, equivalent, geometric and arithmetic mean diameters of seed and its kernel linearly increased with increasing moisture content in all varieties and sizes. The minimum and maximum equivalent diameter of seeds among all varieties and sizes were 5.44 and 9.14 mm respectively. These values for kernels were 4.29 and 5.96 mm, respectively. Among all studied varieties, Shahroodi had Maximum surface area for both seed and kernel. On the other hand, Fandoghi had minimum surface area for both seed and kernel.

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