Two new pyrrole alkaloids, axinellamines A and B, were isolated from the Caribbean marine sponge Axinella sp. and their structures were established on the basis of spectroscopic data, including 2D NMR spectroscopy. Axinellamine A was determined to be 2-((E, E)-6-methyl-2,4-octadienyl)pyrrole while axinellamine B was a dimer of axinellamine A, but containing an additional Me2C unit between the C-5 and C-5′ carbons of the two pyrrole rings.