CdSe nanoclusters of about 22 mn average size have been synthesized by a surfactant-assisted chemical method at room temperature. The asgrown nanoclusters were near stoichiometric and 70% of them were of hexagonal wurtzite crystalline phase. With undefined shapes, the crystalline nanoclusters remained arbitrarily oriented in a compact powder form. The morphology and structural behavior of the nanoclusters were studied by scanning electron microscopy and transmission electron microscopy. Thermal stability of the nanoclusters was studied by thermogravimetric analysis. Presence of very small clusters (<5 nm) in the sample revealed a blue shifted excitonic absorption peak along with the excitonic peak of bigger clusters. (c) 2007 Elsevier B.V. All rights reserved.