Spizaetus nanus is threatened by the extensive habitat destruction within its range, which is reducing, fragmenting and degrading the available lowland forest. It may be tolerant of some habitat degradation, as it has been recorded in heavily logged forest, although it requires tall trees for nesting.
Spizaetus nanus occurs in southern Tenasserim, Myanmar, peninsular Thailand, peninsular and East Malaysia, Kalimantan and Sumatra, Indonesia and Brunei, where it has been recorded in lowland rainforest up to 1,000 m, although some regard it as an extreme lowland forest specialist.
Spitzaetus nanus is widespread but uncommon on Borneo and Sumatra and uncommon or rare in Thailand. The population is thought to have decreased by 50% over the last 10 years, with a projected loss of another 50% over the next ten years with severe fragmentation into subpopulations with less than 1000 mature adults each.
Spitzaeus nanus is regarded as "Vulnerable" by the IUCN Red list.