During the past 80 yr considerable attention has been sporadically directed on benefits derived from consumption of milk products containing Lactobacillus acidophilus. Most earlier work dealt with the use of fermented acidophilus milk to treat intestinal infections. More recent studies have focused on other aspects of health or nutritional benefits that might be derived from this organism. These studies have shown that consumption of milk products containing L. acidophilus has the potential for: 1) preventing or controlling intestinal infections, 2) improving lactose digestion in persons classified as lactose maldigestors, 3) helping control serum cholesterol levels, and 4) exerting anticarcinogenic activity. Based on newer knowledge of L. acidophilus, a single strain of the organism probably will not produce all these benefits at optimal levels. Careful selection of specific strains of L. acidophilus combined with proper production and handling procedures will be necessary to ensure that desired benefits are provided to consumers.