Nowitzki, who ranks seventh on the NBA's all-time scoring list, announced his decision to compete at EuroBasket 2015 on Thursday morning at a news conference in Frankfurt, Germany.
"I've chosen to be in Berlin," Nowitzki said, according to the EuroBasket website, referring to the host city for Group B in this year's tournament. "I've had the whole month of May and used it to gain some distance and enjoy family time. Of course, I also have consulted the matter with my wife.
"But a EuroBasket in our home country is a huge thing and I look forward to it, I thought it would be a great way to conclude my national team career."
Nowitzki, who cites leading Germany to the 2008 Olympics as one of the highlights of his career along with the Mavs' 2011 championship run, opted to retire from international competition after the 2011 EuroBasket tournament. That came after years of Mavs owner Mark Cuban crusading against NBA player participation in FIBA events.
However, Cuban understood the emotional pull of Nowitzki representing Germany in his home country and did not attempt to influence his decision.
"I think it's great," Cuban told ESPN.com through the Cyber Dust messaging app Thursday. "Games are being played in Germany. It will be a chance for his fans there to see him play."
The 37-year-old Nowitzki, who hopes to help Germany qualify for the Olympics again, decided that the increased wear and tear was worth it entering his 18th NBA season.
"If [the EuroBasket tournament] was anywhere else, at the age of 37, it probably would have been a no-go for me," Nowitzki said. "But when I heard that EuroBasket would be played in Berlin, a great basketball city, it was something I had dreamt about."
In self-deprecating fashion, Nowitzki joked that Germany benefited from the Mavs' first-round playoff exit to the Houston Rockets.
"Like every year, the DBB (German Basketball Federation) let me take my decision after the NBA season and, in the end, the national team was lucky that we lost so early," he said.
The EuroBasket tournament, which features Spain, Serbia, Turkey, Italy and Iceland in Group B along with Germany, will be played in September, the month before NBA training camps begin. The national team's training camp begins in mid-August.
"It's so great that Dirk will support us," German coach Chris Fleming, an American, said. "We do not need to talk about his quality as a player on the court, but I cannot emphasize enough how important his presence will be to our younger players."