Management of introduced deer in New Zealand has long been controversial. Deer were introduced into native ecosystems previously free of large mammals, driving unwanted changes in those ecosystems. In national parks, where protecting the native biota is a primary aim, deer and other introduced species are effectively designated as pests, with the law stating that they ‘shall as far as possible be exterminated’. However, deer are too widespread for that to be affordable and they are also valued as a hunting resource by some stakeholders. We describe the management of New Zealand’s only wild herd of wapiti (Cervus canadensis), the Fiordland National Park herd. The Fiordland Wapiti Foundation (FWF) generates revenue from recreational hunters and aims to improve the recreational trophy hunting value of the wapiti herd without increasing unwanted impacts on the native biota. The FWF also manages and (when necessary) subsidises commercial helicopter-based hunting for venison. The commercial hunters take the greatest numbers of deer but target only sympatric red deer (C. elaphus) and red deer–wapiti hybrids, aiming to reverse the loss of wapiti genes from the population whilst ensuring the unwanted impacts of deer are no worse than in unmanaged areas elsewhere. A key issue is determining deer densities and density–impact relationships, and how to affordably measure these. We discuss the underlying principles and complexities implicit in this management system, and assess whether it provides a useful model for the management of some other deer herds of special interest to New Zealand hunters.