In this work, polyvinyl alcohol (PVA) fibers were used as a polymer matrix containing ultra-dispersed diamond (UDD) nanoparticles. Growth of diamond fiber-like structures and films by microwave plasmaenhanced chemical vapor deposition was studied as a function of UDD concentration in the PVA matrix. The influence of surface tension (fibers radii) for nucleation/seeding is discussed. Using a high UDD concentration in the polymer matrix lead to the formation of fiber-like structures. The composite PVA polymer nanofibers with the highest concentration of UDD nanoparticles resulted in the growth of nearly continuous diamond film at low thickness of 250 nm. (C) 2014 Elsevier B.V. All rights reserved.