Schilling announced the news Wednesday on social media. He thanked his Boston-based medical team.
As of yesterday I am in remission. Start the 5 year clock!- Curt Schilling (@gehrig38) June 25, 2014
He announced his diagnosis in February, saying he planned to "embrace this fight, just like the rest of them, with resolute faith, and head on."
He hadn't indicated the type of cancer or his prognosis, but has posted pictures of himself undergoing treatments.
Last month, Schilling made his first public appearance since finishing the cancer treatments, appearing at Fenway Park as the Red Sox celebrated the 2004 World Series-winning team.
Schilling, 47, pitched in the majors for 20 seasons with the Baltimore Orioles, Houston Astros, Philadelphia Phillies, Arizona Diamondbacks and Red Sox. The six-time All-Star finished with a career record of 216-146 and a 3.46 ERA. His 3,116 strikeouts rank 15th all time.
Last year, Schilling told The Boston Globe he had a heart attack in November 2011 and had surgery to place a stent in one of his arteries. He said he experienced chest pains while watching his wife, Shonda, run in the New York City Marathon.
Shonda Schilling also battled cancer after being diagnosed with stage 2 malignant melanoma in 2001.
After his baseball career, Curt Schilling launched a video game company, 38 Studios, whose collapse is the subject of a lawsuit in Rhode Island after it got a $75 million state-guaranteed loan.
Schilling has said he lost as much as $50 million in 38 Studios.
Information from the Associated Press was used in this report.