A new dimeric aporphine alkaloid, phoenicanthusine (1), and six known alkaloids were isolated from the stem bark of Phoenicanthus obliqua. The structure of 1 was elucidated by 1D ((1)H, (13)C) and 2D ((1)H-(1)H COSY, HMQC, HMBC, and NOESY) NMR and HRMS studies. Phoenicanthusine represents the first example of a N-6--C-4' and C-7--C-5' linked dimeric aporphine alkaloid.