The activity of an ethanolic extract of Galipea officinalis bark against Mycobacterium tuberculosis was shown to reside mainly in the basic alkaloidal fraction although the major part of the alkaloids present were in the neutral fraction. Six alkaloids were isolated from the bark including two other alkaloids not previously reported from G. officinalis and a new quinoline named allocuspareine, whose structure was determined by spectroscopic methods. 1H- and 13C-NMR spectral data for three of these compounds are reported for the first time. Isolation and testing of fractions and individual alkaloids against ten strains of M. tuberculosis showed that all the alkaloids possessed some activity but that the unidentified most polar basic fraction exhibited the greatest effect.