Adhesion, structural and optical properties of spin coated PANI/PMMA composite thin films of different composition on glass substrate are reported. The effect of post-deposition heating for 100 degrees C, 125 degrees C and 150 degrees C is also reported. The adhesion of the film was found to increase from 712 +/- 5 x 10(4) N/m(2) to 1602 +/- 3 x 10(4) N/m(2) and refractive index decreased from 1.852 +/- 0.005 to 1.650 +/- 0.004 with increase in concentration of PMMA. Due to post-deposition heating adhesion, optical band gap increased but refractive index decreased. (C) 2008 Elsevier B. V. All rights reserved.