Inheritance of a twisted pod characteristic, in which bean pods develop with a twist that sometimes exceeds 360°, was studied in crosses between round-podded green bean cultivars. In crosses between `Oregon 91G' (normal) or `Oregon 54' (normal) and OSU 5256-1 (twisted), the F1 was normal. Segregation in F2 populations, tested over a 4-year period and including 4,995 plants, clearly fit a 3 normal: 1 twisted ratio. All plants of backcrosses of the F, to the normal parent were normal and backcrosses of the F1 to the twisted parent segregated 1 normal: 1 twisted. The ratios observed indicated that twisted pods are conditioned by a single recessive gene for which the symbol tw is proposed.