In this work, we synthesized In₂S₃ powder through chemical bath deposition method (CBD) in acid medium; we used thioacetamide as sulphide source and InCl₃ as indium ion source. X-ray diffraction, diffuse reflection, and Raman spectroscopy measurements were used for In₂S₃ powder physicochemical characterization. Optical analysis indicated that In₂S₃ was active in the visible region of electromagnetic spectrum; it had a band gap of 2.47 eV; the diffraction patterns and Raman spectroscopy suggested that powder had polycrystalline structure. Furthermore, we also studied the adsorption process of methylene blue (MB) on In₂S₃ powder; adsorption studies indicated that the Langmuir model describes experimental data. Finally, photocatalytic degradation of MB was studied under visible irradiation in aqueous solution; besides, pseudo-first-order model was used to obtain kinetic information about photocatalytic degradation; results indicated that the powder catalyst reduces 26% concentration of MB under visible irradiation.