A novel process of electrolytic copper alloy modification by carbon nanotubes (CNT) was investigated. Modification was carried out in traditional casting process where a specially fabricated modifier was introduced into molten metal before pouring. Mechanical properties and thermal conductivity of the obtained alloy were examined. Tensile tests evaluated that incorporation of 0.01 wt% of CNT improved ultimate tensile strength and yield strength of the alloy by 20% and 10%, respectively. Hardness of 0.01 wt% modified CNT alloy was also enhanced by 28%. Thermal conductivity tests were performed as well and evaluated the temperature-sensitive improvement by 40-50% in thermal conductivity of the modified copper alloy. Simultaneous improvement in mechanical properties and thermal conductivity of the alloy were attributed to the presence of the CNT inside the bulk of the alloy.