A series of Sm3+ doped Lu2O3 nanoparticles have been synthesized via a simple co-precipitation method using oxalic acid as precipitant. The obtained compounds showed a platelet-like morphology with diameter ranging between 10 and 14 nm. The cell parameters increased with the increase of doping, due to the substitution of Lu3+ with larger Sm3+; also a progressive increase of the lattice strain has been induced. Sm3+ doped Lu2O3 nanoparticles showed interesting Vis and NIR emission, which was carefully evaluated together with lifetime measurements. In particular, the system with the lowest Sm3+ loading exhibited the best photoluminescence performances. Preliminary cell viability test evidenced that Sm3+ doped Lu2O3 nanoparticles are not toxic, underlining their potential application a NIR luminescent probes in bioimaging. (C) 2016 Elsevier Ltd. All rights reserved.