The growth curves of Azospirillum lipoferum 4B and Azospirillum brasilense NO 40 grown on raw whey, deproteinized whey and malate media were investigated in batch culture. A maximal cell density of 14 × 108 and 4.5 × 108 cell/ml were attained after 72 h of the growth of Azospirillum brasilense NO40 and Azospirillum lipoferum 4B on deproteinized whey medium respectively. Raw whey as well as deproteinized whey was successfully utilized by both strains in a similar manner to that of malate. The highest growth of A. lipoferum 4B and A. brasilense NO40 was detected when 20 ml/l of raw whey or deproteinized whey were used as a carbon source in the basal medium. Prospective economic balance for the capital cost of malate and whey or deproteinized whey growth media was also discussed.