In our continuing search for novel antiplatelet, antiallergic, and antiinflammatory agents, 2-alkoxy derivatives of 1,4-naphthoquinone were prepared. Some of these compounds showed significant antiplatelet, antiallergic. and antiinflammatory. activities. Among them, 2-propoxy-1,4-naphthoquinone and 2-butoxy-1,4-naphthoquinone exhibited potent inhibitory effect on neutrophil superoxide anion formation. These two compounds are worthy of further exploration.