We demonstrate a synthesis procedure for EuS nanoparticles, which involves the thermolysis of a molecular single-source precursor, europium diethyldithiocarbamate complexed with 1,10-phenanthroline. This technique provides substantial control over the synthesis of EuS nanoparticles within the sub-2 nm size regime. The thermolysis procedure of a single-source EuS precursor was studied by thermogravimetric analysis (TGA) and derivative thermogravimettric analysis (DTG). The particle size and crystallinity were characterized by aberration-corrected scanning transmission electron microscopy (STEM). This thermolysis procedure can be adapted to accommodate other lanthanide-based precursors to yield a variety of lanthanide chalcogenide nanomaterials. (C) 2009 Elsevier B.V. All rights reserved.