Dinwiddie, engaged in a career season for the surging Nets, is expected to miss three to six weeks, league sources told ESPN.
He met with two New York-based hand specialists late this week and both recommended the surgical option, sources said. The Nets have won 20 of 25 games to move into sixth place in the Eastern Conference, and Dinwiddie has been an immense part of the franchise's ascent.
Dinwiddie signed a three-year, $34.5 million extension in December and has moved to second among league reserves in points per game (17.2) and assists (5.0).
The Nets are hoping to get back guard Caris LeVert sometime in February, who has been out since mid-November with a dislocated right foot.
Nets coach Kenny Atkinson said veteran guard Shabazz Napier will move into Dinwiddie's role during his absence.
ESPN's Ian Begley contributed to this report.
Dinwiddie picks up 29 in Nets' win
Spencer Dinwiddie scores 29 points in the Nets' 114-110 win over the Magic, improving to 9-2 in January.