In 1972, he won a George Polk Memorial award for Community Service because of two series of articles he wrote—one on conflicts of interest and mismanagement at Washington area non-profit hospitals, and a second series exposing kickbacks among lawyers, title insurance companies, realtors, and lenders in connection with real estate settlements, inflating the cost of buying homes.

In 2014, Franklin Pierce University awarded Kessler the Marlin Fitzwater Medallion for excellence as a prolific author, journalist, and communicator.

The Washington Post called it "relentlessly uncharitable", a "sour and mean-spirited book", noting that "the author frequently resorts to speculation, guesswork and innuendo.

His unparalleled access to top players in America's counterterrorism campaign allowed him a rare glimpse into their tradecraft, making The Terrorist Watch a riveting account.

Balancing the sordid tales are the kinder stories of presidential humanity ..."[23] Newsweek said of the book, "Kessler's such a skilled storyteller, you almost forget this is dead-serious nonfiction ...

"[25] Kessler's 2011 book The Secrets of the FBI presents revelations about the Russian spy swap, Marilyn Monroe's death, Vince Foster's suicide, the raid on Osama bin Laden's compound, and J. Edgar Hoover's sexual orientation.

[32] However, Marc Ambinder's review in The Week called the book's details "salacious" and "cringe-worthy", noting a "surprising number of weird inaccuracies" that led him to believe "Kessler seems to have listened to his sources, written their words down, and then simply printed as fact their allegations or observations without checking on them.

... Kessler also got Trump to sit down for an interview on New Year's Eve at Mar-a-Lago, a conversation that shows the president confident and comfortable in his role.

[38] In a Time magazine opinion piece, Kessler wrote "The Secret Service Thinks We Are Fools" after the White House intrusion based on his book The First Family Detail.

[39] On January 4, 2010, Kessler wrote a Newsmax article revealing that the Secret Service allowed a third uninvited guest to attend President Obama's state dinner for Indian Prime Minister Manmohan Singh besides party crashers Tareq and Michaele Salahi on November 24, 2009.

"[40] In an article for Newsmax, on March 16, 2008, Kessler incorrectly reported that Senator Barack Obama attended a service at Chicago's Trinity United Church of Christ on July 22, 2007, during which Jeremiah Wright gave a sermon that blamed world suffering on "white arrogance".

[41] Shortly after the controversy broke, Kessler confirmed to Talking Points Memo that he attempted to remove information documenting it from his English Wikipedia biography.

Too often, Kessler seems to have listened to his sources, written their words down, and then simply printed as fact their allegations or observations without checking on them.In a note to The Week, Kessler disputed charges of inaccuracy, including uncertainty over whether then-Vice President Joe Biden had spent a million dollars of taxpayer funds to take personal trips on Air Force Two back and forth between Washington and his home in Wilmington.

During the Bush administration, hoping for some good, ego-enhancing publicity, Sullivan broke with his agency's long-standing policy of absolute silence and allowed Ronald Kessler to get an earful.

But rather than use that wealth of information to write a serious book examining the inner workings of the long-veiled agency or the new challenges of protecting the first black president, the author simply milked the agents for the juiciest gossip he could get and mixed it with a rambling list of their complaints.A September 30, 2014 Politico piece by Kessler on Secret Service blunders, including allowing a knife-wielding intruder to race into the White House and failing to detect gun shots at the White House until four days later,[47] was criticized by Josh Marshall of Talking Points Memo for allegedly implying that because he had not taken steps to correct the problems within the agency by replacing the director, President Obama would be at fault if the Secret Service's security breakdowns led to his own assassination.

[49][50] In a comment to The New York Times, Kessler said he corroborated what he was told with the FBI, and he called the Senate report discredited because it was written only by Democratic lawmakers and did not include interviews with many of the main players.