Although the Northern Goshawk Accipiter gentilis is not designated a threatened species in Japan, it is thought that its population once experienced a decrease. To evaluate the current status of the goshawk, we sequenced the mitochondrial DNA control region and determined its variation among individuals. Considering that part of the Japanese population migrates or moves seasonally, we divided the samples into two categories (breeding and non-breeding season, based on sampling dates) and then calculated indices of genetic diversity and statistics for each category. Among 145 samples, we found ten haplotypes, of which two were dominant in both frequency and range. Haplotype diversity and nucleotide diversity were 0.63±0.04SD and 0.0018±0.0014SD, respectively. Comparing this diversity with those of other species, we concluded that the status of the Northern Goshawk in Japan is neither urgent nor secure. Significant genetic distance was not detected between the breeding and non-breeding groups, thus we could find no evidence of seasonal movement. The long-term effective female population size was estimated at 3,000 to 30,000 individuals. A recent population decline was not detected from the mismatch distribution. Therefore, the past population decline of the goshawk may not have been very serious. Future studies should consider the genetic structure of goshawks that inhabit other areas near Japan.