Waihi, in the Hauraki Goldfield, New Zealand, hosts a world-class epithermal Au-Ag district with a total known endowment of >10 Moz Au and 73M oz Ag.The Martha system was mined underground historically from 1882 to 1952, producing 4.9 Moz of Au and 29 Moz of Ag from workings reaching more than 600 m below the surface and covering an extent of 1.5 x 0.5 km. Mining re-commenced in the Martha open pit between 1988 and 2015, with modern underground mining undertaken continuously from 2004 to the present day at the Favona, Moonlight, Trio and Correnso deposits.Investment in organic growth through brownfields exploration at Waihi has increased following the acquisition of the operation by OceanaGold Limited (OGL) in 2015.Recent exploration programmes have led to up to ten exploration diamond drill rigs operating concurrently to advance brownfields exploration and resource development in the prolific Waihi camp. Near-mine and resource-conversion drilling in 2018 totalled ~50 km.CITATION: Crawford-Flet, L, 2019. Exploration of epithermal quartz vein systems at Waihi, Hauraki Goldfield, in Proceedings PACRIM 2019, pp 252255 (The Australasian Institute of Mining and Metallurgy: Melbourne).