CdS nanoparticles functionalized by electroactive oligothiophenes, with narrow size distribution, have been prepared and characterized. The structure of the hybrid product was investigated by TEM, XRD, optical and FTIR spectroscopy. The modified nanoparticles consist of a few tens of oligothiophene units attached to the CdS core. The grafting of conjugated oligomers to nanoparticles was made possible by complexing the dangling cadmium ion on the nanoparticle surface.