Copper (Cu) gained its importance in several applications due to its attractive thermal characteristics. However, its applications are limited, wherever high strength and high thermal conductivity are desirable. Thus, an attempt was made to develop Cu/CNT composites having the improved mechanical and thermal properties. Initially, Cu/CNT composite powder was synthesized through molecular level mixing technique, where the functionalized 20-40 nm and 40-60 nm diameter CNT with varying concentrations from 0.25 to 1.0 wt.% with an increment of 0.25 wt.% were used. The powder was uniaxially compacted at 800 MPa and sintered in the range of 2-8 hr at 900 degrees C. The best characteristics of Cu/CNT composites obtained from the present study are as follows: Relative density (RD) - 89.1%, Hardness -61.2 +/- 0.58 VHN, Thermal conductivity - 343 W/mK and these characteristics obtained their maximum value at 0.25 wt.% CNT concentration and started to decrease irrespective of CNT diameter. (C) 2018 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.