North Pacific armorhead (Pentaceros wheeleri) was previously considered rare and was sporadically captured in the eastern and western North Pacific. In 1967, an exploratory bottom trawler of the Soviet Union discovered large aggregations of this species associated with the summits of the Southern Emperor–Northern Hawaiian Ridge (SE-NHR) seamounts. The large trawl catches attracted the participation of commercial bottom trawl fleets of the Soviet Union, Japan, and Korea. Although exploratory fisheries and scientific surveys collected some basic information on the biology of this species, large uncertainties remain due to its peculiar life history. Here we describe the current knowledge and information gaps for the biology and ecology of this species through a review of original scientific literature. The life cycle of this species consists of pelagic and demersal stages. Juvenile and immature fish are widely distributed over the subarctic surface waters of the central and eastern North Pacific Ocean. P. wheeleri undergo a protracted initial pelagic phase of 2+ yr (perhaps up to 4.5 yr) in the epipelagic zone. Subadult fish ≥25 cm in fork length recruit to the summits and upper slopes of the SE-NHR seamounts in spring or summer. There are large episodic fluctuations in recruitment to the seamounts that are not predictable or understood and these events obscure the determination of a spawner-recruit relationship. After seamount recruitment, body growth ceases, and the demersal reproductive phase begins. Spawning has only been confirmed around SE-NHR seamounts and occurs from November to February. Large fluctuations in recruitment, difficulties in determination of age and other life history parameters, and the occurrence of fishing grounds on the high seas make the stock assessment and management of this species challenging.