A new alkaloid, named hystrixnine (1), and five known indole alkaloids, ibogamine (2), olivacine (3), affinine (4), affinisine (5) and N b-methylaffinisine (6), were isolated from the root bark of Tabernaemontana hystrix. The known triterpenes α-amyrin acetate, β-amyrin acetate and lupeol acetate were also identified. The structures of the compounds were elucidated based on spectroscopic studies. ©2005 Sociedade Brasileira de Química.