The Fourier-transform infrared (FT-IR) spectra of magnesium phthalocyanine (MgPc) were investigated in the spectral range 500–4000 cm -1 . The spectra allow characterization of vibration modes. A comparison of absorption spectra of powder, as-deposited and annealed films is presented. The dark electrical resistivity measurements were carried out at different temperatures in the range 308 to 423 K. Two activation energies Δ E 1 = 0.23 eV and Δ E 2 = 0.69 eV were obtained. The thermal activation energy Δ E 1 is associated with impurity conduction and Δ E 2 is associated with intrinsic conduction. The current density-voltage characteristics of MgPc at room temperature showed a linear ohmic conduction mechanism at low voltages. At higher voltages the space-charge-limited conduction (SCLC) accompanied as a single dominant level. The temperature dependence of current density allows the determination of some essential parameters such as the hole mobility ( μ h ), the trapping factor Θ and the total trap concentration ( N t ).