We first report the successful quick synthesis of water-soluble ZnTe nanoparticles (NPs) by a hydrothermal technique. The use of N-acetyl-L-cysteine as a ligand and adjustment of the precursor solution pH to 10.3 +/- 0.2 are believed to play key roles in the quick synthesis of ZnTe NPs with a high photoluminescence quantum efficiency of 15%. The reaction time is at least 140-fold quicker than previous work. The results surely indicate the potential of NPs in biomedical applications as a novel type of fluorescent nanoprobe.