CdIn2Se4 semiconductor is known as a high performance electrical material. In this study, CdIn2Se4 powder was synthesized via an aqueous chemical reduction, or a solution method, at low temperature, using Se metal, InCl3, and CdCl2·2.5H2O as precursors, NaBH4 as a reducing agent, and water as a solvent. Preparative parameters have been considered; reaction temperature at 100 and 130 °C, reaction time at 30 min and 6 h. Finally, product powders were characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy techniques. The CdIn2Se4 phase was observed to occur in some preparative conditions with In(OH)3 contaminating phase. However, In(OH)3 impurity has disappeared when the reaction temperature was 130 °C with a reaction time of 30 min, confirmed by XRD patterns. Particle size of product powders was measured from TEM micrographs to be 9.17 ± 0.94 nm.