The temperature dependence of the conductivity and thermopower of TlCoS2 is studied over a wide range of temperatures (77–400 K). It is found that TlCoS2 is characterized by p-type conductivity in the temperature interval 77–225 K and that an inversion of the sign of the thermopower occurs at 225 K. The heat capacity of the ferromagnetic compound TlCoS2 is also measured in the temperature interval 55–300 K. It is shown that the behavior of the magnetic part of the heat capacity of TlCoS2 is typical of a quasi-low-dimensional magnet. The experimental data on the temperature dependence of the heat capacity are used to calculate the thermodynamic parameters of TlCoS2: the changes in entropy and enthalpy.