A large number of copper artefacts from the Chalcolithic period (c. 1500-800 BCE) have been excavated from the Chotanagpur Plateau, a region that extends across the states of Jharkhand, Bihar, Orissa, Madhya Pradesh (presently parts of north-western Chhattisgarh) and West Bengal of the Indian subcontinent. In this paper, I discuss the typological and technological variations observed in the large collection of copper artefacts housed at Patna Museum in Bihar. This research shows that beginning in the Chalcolithic the majority of copper artefacts reported are weapons and agricultural tools. The artifacts which are of initial phase of Chalcolithic period have rough outer texture and clearly show unrefined finishing. Artefacts come in various shapes and sizes, and a diversity of technologies appear to have been applied in the manufacture of the copper implements, including dhokra, casting, the lost-wax method, gilding, forging and hammering. Overall, copper seems to have been used in the production of agricultural tools rather than weapons. But there are some very distinct artefact typologies that are representative of a particular region. For example, copper hoard finds from Ganga-Yamuna Doab do not contain double-edged axes, whereas similarly dated assemblages from the Chotanagpur area and West Bengal have not produced anthropomorphic figures, antennae swords or the hooked spearheads found in the Ganga-Yamuna Doab, but they do contain double-edged axes.