The synthesis of Eu3+:Sr2CeO4 nanocrystals prepared by a modified sol-gel method is reported. The nanocrystalline powders were annealed at different temperatures to control the average grain size of nanocrystals. The absorption, emission and excitation spectra of Eu3+:Sr2CeO4 nanocrystals were investigated in a temperature range of 10-300 K. In particular the influence of temperature and average nanocrystal size on the optical properties of Eu3+:Sr2CeO4 was investigated. It was found that with increasing grain size the luminescence lifetimes significantly decreased. The shortening of lifetimes was extremely strong at elevated temperature. Due to the strong temperature dependence of the f-f and charge transfer (CT) luminescence intensity ratio the Eu3+:Sr2CeO4 nanocrystals can be used in the long contact temperature sensing. (C) 2015 Elsevier Ltd. All rights reserved.