The use of irradiation to increase longevity and quality of horticultural commodities often results in undesirable softening. The biochemical basis of irradiation-induced softening is not well understood. In this study, we investigated the role of the pectic polysaccharides in irradiation-induced textural changes of `Sunny' tomato fruit. `Sunny' mature-green and pink fruit subjected to 84 or 240 Krad experienced a dosage-dependent decrease in firmness, an increase in electrolyte leakage, and an increase in chelator-soluble pectins. Additionally, pectins prepared from 240 Krad-irradiated fruit were of markedly lower mol wt compared to those from nonirradiated fruit. Irradiation-induced downshifts in pectin mol wt were also noted for preripe fruit that lack PG activity. Mol wt decreases noted for pectins from 240 Krad-treated fruit exceeded those observed for fully ripe, nonirradiated fruit The role of other cell wall polymers in irradiation-induced textural changes is currently being addressed.