Abstract. It has been observed by various imaging and spectral instruments that wave and oscillatory phenomena frequently occur in different coronal magnetic structures. In coronal loops and solar prominences these oscillations are interpreted as slow magneto-acoustic waves. In this paper we study the spatial damping of linear non-adiabatic slow magnetoacoustic waves in a homogeneous, isothermal, and unbounded coronal plasma permeated by a uniform magnetic field, with physical properties akin to those of coronal loops. We consider an energy equation with optically thin radiative losses, thermal conduction, and heating, and linearize the MHD equations to obtain a fourth-order polynomial in the wavenumber k, which represents the dispersion relation for slow and thermal MHD waves. Since we are interested in the spatial damping, we have taken angular frequency Ïas real and have numerically solved the dispersion relation to obtain complex solutions for the wavenumber k corresponding to slow and thermal waves. It has been found that damping length of slow-mode waves exhibit varying behavior depending upon the physical parameters of the loop.