Acylfulvene analogs, which inhibit tumor growth, especially solid tumor growth, and which have an adequate therapeutic index to be effective for in vivo treatment are provided herein. The compounds described herein are useful as anti-neoplastic agents, i.e., to inhibit tumor cell growth in vitro or in vivo, in mammalian hosts, such as humans or animals, e.g., domestic animals, and are effective against solid tumors, hematologic malignancies and multi-drug resistant cancers/tumors. The present compounds can be used alone or they can be used in combination with one or more anti-cancer or anti-tumor agents.