The objective of this research was to study the effect of various parameters such as temperature and pH to the formation of cadmium indium selenide (CdIn2Se4) thin films, which were fabricated by sol–gel dip-coating method. This n-type semiconductor compound is suitable for application as thermoelectric materials. Cadmium, indium, selenium precursors were separately dissolved by solvents: ethanol, hydrochloric acid, and acetic acid to form metal alkoxides. The precursor solutions were then mixed together in N2 atmosphere. These metal alkoxides were hydrolyzed by adding water and then polycondensed by adding ethylene glycol to become gels. These gels were adjusted to various acid-base values by adding diethylnolamine. Glass substrates were dipped into the gels to form thin films. These thin films were annealed at various temperatures in N2 atmosphere and characterized by scanning electron microscopy (SEM), x-ray diffraction (XRD) and fourier transfrom infrared spectroscopy (FTIR) techniques. The results indicated that CdIn2 Se4 compound occurred by the reaction at room temperaturewith pH 4 and annealed at 450◦ C inN2 atmosphere.