A series of 6,11-dihydrodibenz[b,e]oxepin-2-acetic acids has been evaluated for both antiinflammatory and analgetic activity in the carrageenan paw edema and phenylquinone writhing assays. The requirements for optimal activity in this series appear rather specific: (a) an unsubstituted 6,11-dihydrodibenz[b,e]oxepin nucleus and (b) a carbonyl group in the 11 position. One derivative, 6,11-dihydro-11-oxodibenz[b,e]oxepin-2-acetic acid (11), has been selected for further study.