A total of 29 strains of Brucella abortus, B. melitensis, B. suis, B. ovis, and B. neotomae were examined for growth and catechol production in a semisynthetic low-iron medium. All strains showed reduced growth yields and, quantitatively, production of catechols varied widely among the different strains with no relationship to species, biotypes, or serotypes of Brucella. No clear correlation between catechol production and growth under iron-limiting conditions was observed. The major catechol was identified as 2,3-dihydroxybenzoic acid, and neither other iron-regulated catechols nor hydroxamate type compounds were detected when representative strains of B. abortus or B. melitensis were grown in tryptic soy broth in the presence of iron-sequestering agents.