Changes in distribution patterns and demand for increased food quality have resulted in a desire to improve the shelf life of nonsterile dairy products. Refrigerated shelf life extension typically requires, at a minimum, reductions in the growth rate of spoilage microorganisms and subsequent product deterioration. Reducing initial bacterial loads, increasing pasteurization regimes, and reducing postprocessing contamination have all been employed with measured success. The use of antimicrobial additives has been discouraged primarily due to labeling requirements and perceived toxicity risks. Carbon dioxide (CO 2 ) is a naturally occurring milk component and inhibitory toward select dairy spoilage microorganisms; however, the precise mechanism is not fully understood. CO 2 addition through modified atmosphere packaging or direct injection as a cost-effective shelf life extension strategy is used commercially worldwide for some dairy products and is being considered for others as well. New CO 2 technologies are being developed for improvements in the shelf life, quality, and yield of a diversity of dairy products, including raw and pasteurized milk, cheeses, cottage cheese, yogurt, and fermented dairy beverages. Here we present a comprehensive review of past and present research related to quality improvement of such dairy products using CO 2 .