In business, a cash cow is a product or a business unit that generates unusually high profit margins: so high that it is responsible for a large amount of a company's operating profit. This profit far exceeds the amount necessary to maintain the cash cow business, and the excess is used by the business for other purposes. The expression is a metaphor for a dairy cow, which after being acquired can be milked on an ongoing basis with little expense.

Risks of a cash cow include complacency, with management ignoring the need for change as market forces erode value; and ongoing turf wars between the management in charge of the cash cow and other managers trying to garner support for other products.

That said, every business longs for a cash cow product. The BCG growth-share matrix developed by the Boston Consulting Group, still used by analysts in large companies, uses the term "cash cow" to describe business units experiencing high market share and low market growth.