He studied law at Leiden University, then worked at the Brussels department of (Dutch) European Union commissioner of foreign relations Van den Broek, and was then hired by the EU. He continued to work there in various capacities until the end of 1999. In December 2000, he was awarded a Master of Business Administration at the European Institute of Business Administration in Fontainebleau, France and then spent a summer working for the International Finance Corporation of the World Bank group in Washington D.C
He married (Petra) Laurentien Brinkhorst on May 17, 2001. Following his marriage, Prince Constanijn and his wife moved to London, England where he works for strategic consultants Booz, Allan and Hamilton. They have a daughter Eloise (born June 8, 2002), the first grandchild of Queen Beatrix.
Prince Constantijn rarely attends public events in his capacity as a member of the Dutch Royal House.