2-Methyl-5-(3-phenylpropionyl)-1-benzoxolane (CAS 159264-96-7) was synthesized and studied for anti-inflammatory properties. This new aryl ketone was more active than the previously reported 5-acyl substituted 1-benzoxolanes except 5-cinnamoyl-2-methyl-1-benzoxolane (the unsaturated analogue) which exhibited similar anti-inflammatory activity and similar toxicity but was more gastrotoxic. Anti-inflammatory and analgesic effects of 2-methyl-5-(3-phenylpropionyl)-1-benzoxolane were less pronounced than those of indometacin but greater than those of acetylsalicylic acid (ASA). The new ketone was less toxic and less gastrotoxic than both the reference drugs mentioned above. Therapeutic indices of the new compound were significantly greater than those of ASA and indometacin.