The agency won the account after a competitive pitch that began last year.
Duke/Razorfish will now be responsible for the brand's strategic and creative activity, and will create a campaign for Guerlain's new flagship products in the perfume, skincare and makeup categories.
The agency said it aimed to enhance Guerlain's services, expand its creativity and promote the richness of the Guerlain brand, which has been running since 1828. The company is part of the Louis Vuitton Moet Hennessy (LVMH) group.
Activity will begin in March and focus on new product launches such as a special lipstick launch event, and two initiatives centered on perfume. The work will be mainly targeted for the French, Chinese and Russian markets.
Sonia Voskoboinikoff, communication director, Guerlain, said: "In 2011, Guerlain has made digital one of its priorities and wishes to reorganise its entire digital ecosystem by 2012."