Sponge-induced exudate from the rat and saline extracts of normal rat liver and rat liver damaged in situ by dimethylnitrosamine have been assayed for putrescine, spermidine and spermine levels. The three physiological oligoamines have been examined for anti-inflammatory activity by the carrageenan-induced oedema rat model and spermidine and putrescine were found to be anti-inflammatory with putrescine being about ten times as active as spermidine. Putrescine was also anti-inflammatory in the adjuvant arthritic rat model. Thioacetamide and theophylline were also anti-inflammatory and theophylline doubled the level of putrescine in rat liver. It was concluded that putrescine was a potent anti-inflammatory factor in the inflammatory exudates and extracts examined.