The synthesis, electrical and sensing properties of 7,8-diazabenzo[ghi]perylene (DABP) mixed with multi-walled carbon nanotubes (MWCNTs) have been reported. DABP was synthesized through a photochemical reaction approach and resulted suitable for solution processing, allowing the easy deposition of films on the sensor substrate. Thin films of DABP/MWCNTs composites have shown an electrical behavior depending on the carbon nanotubes loading. Sensing properties of resistive devices fabricated using DABP/MWCNTs semiconducting composites have revealed a high and fast response to relative humidity and vapor of protonated organic solvents.