Fifteen alkaloids were found in the root bark, stem bark and leaves of Alstonia congensis. They are echitamidine, echitamine, nor-echitamine, 17-acetoxy-nor-echitamine, akuammicine, 12-methoxyakuammicine, 12-methoxy-N(4)-methylakuammicine, tubotaiwine, 12-methoxytubotaiwine, angustilobines A and B, 6,7-seco angustilo-bines A and B, angustilobine B-N(4)-oxide and akuammidine. © 1989.