Seclazone possesses anti-inflammatory, analgesic and antipyretic properties. It effectively suppresses the development of adjuvant-induced polyarthritis in rats and the serum protein alterations associated with this condition. Seclazone also prevents phlogistic responses induced in rats by carrageenan. The anti-inflammatory effect of seclazone is not mediated by adrenocortical or pituitary stimulation since activity persists in adrenalectomized or hypophysectomized animals. Seclazone has an appreciable anti-bradykinin action in vitro. The drug is free of ulcerogenic activity at therapeutically active levels and possesses diuretic properties.