We demonstrated the design of tiny bowls of copper-silver-gold (Cu-Ag-Au) alloy type noble trimetallic nanocrystals with a unique shape. All the structural characterizations confirm the presence of copper (Cu), silver (Ag), and gold (Au) in the trimetallic nanobowls. Finally, we examined the catalytic efficiency of trimetallic Cu-Ag-Au nanobowls for reduction of 4-nitrophenol to 4-aminophenol and found that these nanobowls were 14, 23 and 43-fold more active than each of the constituent metals, Au, Cu and Ag, respectively. (C) 2019 Elsevier Inc. All rights reserved.