[5][6] Boies rose to national prominence for three major cases: leading the U.S. federal government's successful prosecution of Microsoft in United States v. Microsoft Corp., his unsuccessful representation of Democratic presidential candidate Al Gore in Bush v. Gore,[7] and for successful representation of the plaintiff in Hollingsworth v. Perry, which invalidated California Proposition 8 banning same-sex marriage.

[11] Journalist Malcolm Gladwell has described the unique processes of reading and learning Boies experienced due to his dyslexia.

[17] He left Cravath in 1997 when a major client objected to his representation of the New York Yankees even though the firm itself had found no conflict.

[23] In 2001, the Washington Monthly called Boies "a brilliant trial lawyer", "a latter-day Clarence Darrow", and "a mad genius" for his work on the Microsoft case.

[27] In 2006, Boies, Schiller & Flexner LLP negotiated a major settlement with The American International Group on behalf of its client, C. V. Starr, a firm controlled by Maurice R. Greenberg, the former chairman and chief executive of A.I.G.

[28] In 2015 Boies won at trial a claim that the government's $85 billion bailout of AIG had been unfair to the company's owners.

[30] In 2009, following the California Supreme Court ruling on Strauss v. Horton, Boies joined former Solicitor General Theodore Olson, the opposing attorney in Bush v. Gore, in the lawsuit Perry v. Brown seeking to overturn the state of California's Proposition 8 ban on same-sex marriage.

Also in 2009, the Golden Gate Yacht Club retained Boies for their ongoing dispute with Société Nautique de Genève regarding the 33rd America's Cup.

[35][36] Boies was part of the legal team representing the National Football League in their antitrust litigation, Brady v.

[38] Boies was the lead counsel for Oracle Corporation in its lawsuit against Google on the use of Java programming language technology in the Android operating system.

[42] In February 2016, Boies agreed to both sit on the board of directors and act as the attorney for troubled Silicon Valley startup.

[56] Over the course of a year, Weinstein had Black Cube and other agencies "target", or collect information on, dozens of individuals, and compile psychological profiles that sometimes focused on their personal or sexual histories.

[61] A few days after The New Yorker broke the story "Harvey Weinstein's Army of Spies", The New York Times announced it had "terminated its relationship" with Boies' firm.

[42] His dual roles as attorney and board member of the defunct company is recounted in the book, Bad Blood: Secrets and Lies in a Silicon Valley Startup by then The Wall Street Journal investigative reporter John Carreyrou.

[42] Boies, along with lawyers Heather King and Michael Brille, and his firm are described as protecting the startup using surveillance of witnesses and journalists, weaponized use of non-disclosure agreements and affidavits, intimidation tactics, and other heavy-handed practices.

[67][68] Boies Schiller Flexner LLP is portrayed by Carreyrou as acting as an extension of Theranos, including the use of the law firm's New York offices for hosting promotional meetings such as a faked blood test administered to Fortune writer Roger Parloff.

[72] Boies eventually left the Theranos board of directors, after the U.S. federal government had initiated multiple investigations into the firm.

[73] Boies owns a home in Westchester County, New York,[74] Hawk and Horse Vineyards in Northern California, an oceangoing yacht, and a large wine collection.

The Boieses give an annual picnic at their home for the incoming Teach for America corps for New York City (300–500 people).