Cuban's first foray in the business world was as a garbage bag and powdered milk salesman, when he sold garbage bags around his neighborhood in the south hills of Pittsburgh. Cuban earned his way to college by giving disco dancing lessons and by writing chain letters. He chose Indiana University because of the school's low cost compared to the nation's other top business schools. Even in college, Cuban was seen as controversial by some: his advisor admonished him for taking advanced courses during his freshman year and he was dissuaded from getting his MBA after getting a bachelor's degree.

Shortly after college, in 1982, Cuban founded MicroSolutions, a system integrator in Dallas. The company was a reseller for companies like Novell, 3Com, IBM, Banyan, Apple Computer and Sun Microsystems and an early adopter of technologies such as Carbon Copy, Lotus Notes, and CompuServe. One of the company's biggest clients was Perot Systems. In July of 1990, Cuban sold MicroSolutions to CompuServe, Inc, a subsidiary of H&R Block, for six million dollars. Soon after selling MicroSolutions, while eagerly following the basketball team of his college alma mater, Cuban and fellow alum Todd Wagner had the idea of broadcasting live games and events through the Internet, which led to the creation of Broadcast.com. In 1999, Cuban sold Broadcast.com for about $5.7 billion to Yahoo!. HDnet