Hierarchical flower-like MoS2 spheres with high purity were synthesized by hydrothermal method using WO3 nanorods or H2WO4 as an additive. The flower-like spheres were about 1 mu m in diameter and built up with MoS2 thin flakes with thickness of several nanometers. Energy disperse X-ray spectrum showed that the spheres were only composed of Mo and S with atomic ratio of 2:1. Powder X-ray diffraction result further indicated that the products were MoS2. The reaction mechanism is discussed and suggested that tungstenic acid played an important role on the formation of flower-like MoS2 spheres. (C) 2007 Published by Elsevier Ltd.