<jats:p> A method is described for the purification of two phenazine compounds from cultures of a strain of Pseudomonas aureofaciens. The chemical properties of the compounds are described and the ultraviolet, visible, and infrared absorption spectra are shown. One compound is identified as phenazine-1-carboxylic acid and the other is probably 2-hydroxyphenazine-1-carboxylic acid.