Pure gamma-MnS films have been deposited on commercial glass slides by chemical bath deposition (CBD) at 60degreesC. Experimental results indicate that both pre-treatment of the substrates by HF etching and control of the reaction temperature play an important role in the formation of crystalline films. The optical absorption measurements reveal that the band gaps of as-deposited amorphous and gamma-MnS films are 3.23 and 3.16 eV, respectively, which agree with the previously reported values. (C) 2002 Elsevier Science B.V. All rights reserved.