Chromosome doubling through seed and multiple shoot treatments was conducted to obtain octoploid kakrol (Momordica dioica Roxb.) plants. Seed treatments with 0.2, 0.4% colchicine or 0.003% amiprophos-methyl were effective to chromosome doubling, among which the treatment with 0.4% colchicine was most effective. Amiprophos-methyl treatment also brought octoploid plants with high rate of seed germination. Multiple shoot treatments with 0.05% colchicine for 12 and 24 hours, and 0.1% colcjicine for 24 hours also brought octoploid plants. Leaf and guard cell size were bigger, and leaf shape index (leaf length/leaf width) was lower in the octoploid than in tetraploid plants. Leaves of the octoploid plants were uneven on the surface with clear serrations.