The dielectric properties of TlInSe2 grown by direct fusion of their constituent elements were studied in the frequency range of 30 KHz-20 MHz, temperature range of 173-373 K. The dielectric constant and dielectric loss of TlInSe2 were calculated by measuring capacitance (C) and dielectric loss factor (tan d). Both of them were found to decrease with increasing frequency and increase with increasing temperature. This behavior can be explained with two polarization mechanisms in the investigated frequency and temperature range. The relaxation times of these polarization mechanisms were obtained from Cole-Cole fits. At lower frequencies the relaxation time is 10(-6) while it was 10(-8) at the higher frequencies. The maximum barrier height (Wm) was estimated from the dielectric loss measurements. The value of W-m was obtained as 0.1 eV. It was found to increase with increasing temperature.