We report evidence for highly efficient Forster resonance energy transfer between CdTe nanocrystals (donors) and Rhodamine B (acceptors) in mixed solid films. Enhancement of the acceptor photoluminescence intensity and a, decrease of the donor decay time are observed in the films containing nanocrystals mixed with Rhodamine B. For a wide range of films with a ratio between the amount of acceptors and the amount of donors of 0.2-5, an efficiency of energy transfer of more than 20% is estimated from time resolved measurements. (C) 2004 Elsevier B.V. All rights reserved.