The printed circuit heat exchanger (PCHE) is a key component in the future compact energy cycles due to its high heat transfer performance and structural rigidity. In this study, the thermal performance of wavy-channeled PCHEs, and the effects of the waviness factors: the amplitude and the period, on the thermal performance of the PCHE are investigated numerically. The thermal performance of the wavy-channeled PCHEs is compared with that of conventional PCHEs with straight channels. Based on the numerical results, it has been shown that the wavy-channeled PCHEs can have significantly higher thermal performance than the conventional straight-channeled PCHEs due to the increased area for heat transfer. The effect of recirculating flow induced by the waviness is estimated to be negligible for the typical range of CO2 mass flow rate of compact power generations. It has been shown that the performance enhancement can be predicted using a sole nondimensional parameter: the ratio between amplitude and period, and has linear relationship with this nondimensional parameter. (C) 2017 Elsevier Ltd. All rights reserved.