Poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate)/silver nanoparticles composite inks have been prepared through in situ synthesis and ultrasonic dispersion. The developed inks were proved to be suitable for various inkjet printing trials to deposit the thin films which were subsequently characterized to assess their electric and optical properties. The results have indicated that the dedoping of PSS from PEDOT during the in situ synthesis can be detrimental to the conductivity of the deposited composite films. However, the addition of silver nanoparticles to pristine PEDOT:PSS has significantly enhanced the conductivity of the thin films, with an inevitable loss in transparency. The various factors that can influence the properties of the thin films have also been analyzed and discussed. This study provides an insight into the effect of silver nanoparticles on PEDOT:PSS thin films deposited using inkjet printing process, and their properties due to the methods of ink formulation. (C) 2013 Elsevier B.V. All rights reserved.