Binary and ternary semiconductor chalcogenides especially from IV-VI group have been very attractive because of their large-scale applications in science and technology. Lead Selenide (PbSe) is important for its narrow bandgap (Eg = 0.27eV), high carrier mobility and dielectric constant. It crystalizes into fcc cubic structure with Fm3m space group. All these characteristics make it unique and important for applications in solid state devices. 10µm long PbSe nanowires have been synthesized using template assisted electrochemical deposition in 80 nm pores of polycarbonate membrane. The synthesized nanowires were irradiated with 120 MeV Au+9 ions at Inter University Accelerator Centre (IUAC), New Delhi, India to study post irradiated induced changes in structural, optical and electrical properties as well as surface morphology using X- ray diffraction, UV- visible, I-V characterization and scanning electron microscopy (SEM) respectively. Electrical study was performed to study the change in resistivity of the nanowires upon swift heavy ion irradiation. The change in efficiency of the thermoelectric material is characterized by figure of merit ZT. Thus, irradiation induced changes in ZT factor of nanowires have also been evaluated to study the efficiency. The detailed results will be discussed during the presentation.