Levamisole potentiated paw oedema induced by carrageenan in the rat whereas penicillamine was without effect. On the other hand, levamisole inhibited paw oedema induced by kaolin, penicillamine again having no effect. The copper complex of penicillamine was inhibitory in the carrageenan test but failed to show inhibition in the kaolin model of inflammation. These results show that levamisole and penicillamine are capable of exerting anti-inflammatory activity in the rat but only under certain conditions.