In this study, the effects of geometrical parameters on the thermal performance and structural stability of wavy-channeld PCHEs compact heat exchangers are investigated numerically. A counter flow wavy-channeld PCHEs are considered in order to improve the thermal performance compared with the conventional straight channel PCHE. In this regard, we considered the effects of waviness factor: the amplitude and wavelength. Also, the effect of channel spacing and diameters are studied regarding thermal performance and structural stability of the wavy-channeld PCHEs. The numerical results show that the thermal performance of the PCHEs can be significantly improved by employing the wavy channels due to the increased surface area for heat transfer. It has been shown that there is an optimal value for the channel spacing and diameters for a fixed value of mass flow. Structural stability is also acceptable based on the safety factor various channel spacing and diameters of wavy-channeld PCHEs. This study can be widely utilized for designing and optimization of the PCHEs.