Thin films of polypyrrole (PPY) were prepared by Matrix-Assisted Pulsed Laser Evaporation (MAPLE) technology from two matrices: water and dimethylsulfoxide (DMSO). The deposition was carried Out using a KrF excimer laser (laser fluence F ranged from 0.1 to 0.6 J cm(-2)). This work deals with optimization of two deposition parameters - laser fluence and number of pulses - for both matrices. From the deposition curves, the fluence thresholds, F(th) and maximum growth rates were subsequently determined (water matrix: F(th)similar to 0.40-0.45 J cm(-2), maximum growth rate 0.16 nm pulse(-1): DMSO matrix: F(th)similar to 0.25-0.30 J cm(-2); maximum growth rate 0.20 nm pulse(-1)). The changes in chemical composition of deposited layers wore studied by Attenuated Total Reflection Fourier Transform Infrared spectroscopy. Surface morphology was characterized by Atomic Force Microscopy. A discussion is also presented concerning relationships between laser fluence and chemical composition of deposited layers with respect to their potential application in gas sensors. Finally, the response of a sensor with a MAPLE deposited PPY active layer to air humidity is presented. (C) 2008 Elsevier B.V. All rights reserved.