A series of six new dibrominated alkaloids, amathaspiramides A-F (1-6), have been isolated from a New Zealand collection of the marine bryozoan Amathia wilsoni. An X-ray crystallographic structural determination of amathaspiramide F (6) revealed it to be an epimer of amathaspiramide C (3). These data, in addition to the results of NOESY NMR experiments were used to infer the absolute configuration of the amathaspiramides.