Polo-likekinase (Plk) 1 is a serine-threonine protein kinase that plays a role in cell division, and its overexpression is highly correlated with aggressiveness and prognosis of many cancers. We have designed, synthesized and evaluated a series of terphenyl compounds as inhibitors of the kinase activity of Plk1. Some of them act as non-ATP-competitivePlk1inhibitors.