Two genetic variants with increased organ size were independently derived from diploid (2n = 2x = 16) chickpea (Cicer arietinum L.) line ICC 640. Radiation-induced mutant PM 101 had greatly enlarged leaves, leaflets, and pods, and an elongated stem with longer intemodes but fewer nodes than ICC 640. F1, F2, and F3 data from crosses with ICC 640 showed that the mutant characteristics of PM 1 101 were the pleiotropic effects of a single, recessive genetic factor. For purposes of comparison, tetraploid derivatives of ICC 640 were produced by colchicine treatment of seed. In the tetraploids, leaflets and pods were enlarged, but less dramatically than in PM 1 101. Enlarged pollen grains and stomatal guard cells, and increased guard cell chloroplast number were found in tetraploids but not in PM 1 101, while both variants produced fewer seeds than ICC 640. Mutant PM 1 101 and the tetraploids represent two very different manifestations of gigantism in chickpea.