Nanoparticles of Y3Al5O12:Ce3+ (YAG:Ce3+, 1%) were synthesized via the glycothermal method. The particle sizes were estimated by transmission electron microscopy, X-ray diffraction, surface area determination and by dynamic light scattering. We found primary particles of 10-14 nm in diameter, which form agglomerates of approximately 100 nm. For the 4f -> 5d transition of Ce3+ an internal quantum efficacy of up to 46% was measured. The particles consist of 6-10% of 1,4-butanediol attached on the surface, as determined by carbon content measurements in combination with IR and absorption spectroscopy. In particular, limiting drawbacks due to inevitable surface coatings for glycothermal syntheses and nanoscale associated scattering are elucidated. (C) 2011 Published by Elsevier Ltd.