The Japanese Spurdog (Squalus japonicus) is a bycatch of demersal trawl, longline, and gillnet fisheries and is retained for human consumption and fish meal. Species-specific catch rates from Japan indicate a relatively stable population over the past 36 years (~one and a half generation lengths). Landings data of all sharks combined from the Taiwan Exclusive Economic Zone (EEZ) and reconstructed catches of all sharks, skates, and rays from the China and South Korea EEZs indicate declines of 52–99% over the past three generation lengths (63 years). These levels of declines are not species-specific but are informative for understanding the broader levels of decline in sharks in the region. Most of the distribution of the species is in Taiwan, China, and South Korea where historic and current fishing pressure is high. The inshore trawl and gillnet bans in Taiwan and China, respectively, may afford the species some refuge from fishing pressure. In Japan, where the population appears stable, fishing pressure and bottom trawl effort is decreasing and continuing to decline. It is inferred that the Japanese Spurdog has undergone a population reduction of 50–79% over the past three generation lengths (63 years) due to levels of exploitation, and it is assessed as ENDANGERED.