Field experiments were conducted at Fayetteville, Arkansas, in spring and fail of 1989 and 1990 to determine the effect of smooth pigweed density and the duration of interference on snap bean quality. Pod length, percentage of fiber, seed weight, sloughing, pod firmness and color of snap bean were not affected by smooth pigweed densities, which ranged from 0 to 75 plants per square meter. Smooth pigweed interference for 38 days increased snap bean pod fiber and firmness. Full-season interference (for 49 days after emergence) delayed snap bean pod maturity. To prevent delay in pod maturity, smooth pigweed should be controlled 28 days after snap bean emergence or before snap bean bloom.