Marriott International Inc. diversified continuously, absorbing the development opportunities that the environment offered. It managed to survive critical times of recession and crisis. Diversification changed the company into what it is today - a giant in the hotel business, whose branches have extended to five continents. The purpose of this case study was to determine if Marriott International Inc. added value through diversification from 1970 to 2000. Six diversification decisions were made that changed Marriott from a foodservice to a hotel firm. These diversification decisions were related to: (1) theme parks, (2) Courtyard by Marriott (entrance to the moderate-priced hotel business), (3) Marriott Suites (entrance to the corporate living business), (4) acquisition of Residence Inns, (5) acquisition of Ritz-Carlton (entrance to the luxury hotel business), and (6) acquisition of Renaissance Hotel Group. The research examined each diversification decision following three major steps: identification of the diversification opportunity and explanation of why it was important to be included in this study, (2) analysis of operating performance measures including sales, net income, earnings per share, sales growth rate, net income growth rate, earnings per share growth rate, and net profit margin, and (3) comparison of the closing price of common stock for Marriott and its competitors. Despite the limitations of this case study and the limited connection between specific diversification decisions and operating and market performance, findings from this research suggest that changing from a foodservice to a hotel firm added value. Moreover, this type of research can serve as a foundation for additional studies attempting to explore and quantify the relationship between diversification and value in the hospitality industry.