9-methoxyellipticine is an indole alkaloid from the roots of Ochrosia acuminata. Antitumor properties of 9-methoxyellipticine were demonstrated. 9-Methoxyellipticine possesses a relatively broad spectrum of antitumor activity, 10 of 17 mouse neoplasms tested having responded. Both intraperitoneal and oral activity have been noted. Significant activity was seen against both the ascites and solid forms of the Walker rat carcinosarcoma 256. 9-methoxyellipticine binds DNA through a single step mechanism, can be considered as a pure intercalator.