We have studied the effect of point defects-on coherent optical phonons and photo-generated carriers in ion-implanted bismuth polycrystalline films and single crystals by means of pump-probe reflectivity technique. The dephasing time of the A(1g) phonon decreases monotonically with increasing ion dose, which is explained by phonon-defect scattering. The relaxation time of photo-excited carriers decreases as the ion dose increases, being attributed to trapping of carriers by defect-induced deep levels. The behavior of the carrier and phonon dynamics for the polycrystalline film is compared with those for the single crystal. (C) 2002 Elsevier Science B.V All rights reserved.