An aqueous, room temperature, and surfactant-less synthetic route based on galvanic replacement and co-reduction is reported to yield PdAgCu nanoparticles (NPs) with a high density of sharp and branched tips. The PdAgCu NPs are of high-purity, uniform size and more than 90% of them adopt branched tips. Besides, the PdAgCu NPs exhibit hollow interiors, well-alloyed nature, and a tuneable localized surface plasmon resonance peak in the near infrared region. Their morphology and optical property are facilely controlled by adjusting the precursor molar ratio, amounts of AgNP seeds and Cl- ions in the growth solution. The proposed synthetic approach is anticipated to offer an attractive avenue for facile synthesis of other multi-metallic and branched NPs with controlled properties.