Pigeon pea-tomato cropping sequence was initiated in July 14, 1993 at Juana Diaz, Puerto Rico to evaluate weed suppression from pigeon pea residues and herbicides. Herbicides such as metribuzin (0.56 kg ai/ha), prometryn (2.24 kg ai/ha), oxyfluorfen (0.28 kg ai/ha), and imazethapyr (0.07 kg ai/ha) applied pre-emergence to pigeonpea decreased weed density up to 100 % for the first two weeks. Weed density increased after four weeks and no differences were detected among herbicides. Pigeonpea yield ranged from 2026 kg/ha (green pods) with imazethapyr to 2980 kg/ha with handwccdings. Weed density was evaluated in a tomato transplanted in the same plots March 4, 1994. Weed density was not significantly different among previous herbicide treatments applied to pigeon pea. Average reduction in weed density' was 57% in plots where pigeonpea was grown and incorporated.