Studies were conducted on some physical properties of Mexican sunflower at 9.68% moisture level using standard methods. The geometric dimensions were found to be within the range for most grass seed and cereals. The low sphericity and bulk density, as a result of the flattish shape of the seed, confirmed that the seeds are expected to slide rather than roll in handling. The low porosity and terminal velocity indicate that the free air flow during drying, aeration and pneumatic separation may be difficult, however, these are useful in separation of the seed from heavier materials such as stone and pebbles.