The objectiv of this research was to verify the effects of seed shape and size upon corn seed quality in the cultivar AL -34. This experiment was carried out under laboratory conditions. Test material consisted of remainders from the corn seed grading, classified by passing through sieves with oblong and round openings, thus obtaining six treatments (seed classes): 20/64in. (7.94mm), 18/64in. (7.14mm), 15/64in. x 3/4 (5.95 x 19.05mm), 14/64in. x 3/4 (5.56 x 19.05mm), 13/64in. x 3/4 (5.16 x 19.05mm) and 12/64in. x 3/4 (4.74 x 19.05mm), which were compared with the commercial standard of the cultivar, seed from the 22/64in. (8.73mm) class. The experimental design used was a completely randomized design. The following tests were run: germination, iodine dye, electrical conductivity, cold test without soil, accelerated aging and weight of 100 seeds. It was concluded that flat seeds were superior to round seeds, based on vigor tests; influence of size on quality of flat seeds was not verified.