Abstract A series of o -hydroxycinnamanilides and the corresponding series of salicylanilide derivatives were prepared and tested for antifungal activity. These compounds were investigated for the purpose of determining the effect of vinylogy and also the effect of substitution on the anilide rings. The results showed that all of the 0-hydroxycinnamanilide derivatives had less antifungal activity than did their corresponding salicylanilide derivatives. Most of the compounds bad some antifungal activity at the tested concentration of 0.5%; however, only two compounds had activity greater than salicylanilide. These compounds were the 3′-chloro- and the 4′-chloro-salicylanilides.