A Jami'an (SSS), A matsayin Department of State Services (Dss), ne hukumomin tsaro na Najeriya da kuma daya daga uku gaje kungiyoyi da National Security Organization (NSO). Hukumar tana karkashin fadar shugaban kasa ta Tarayyar Najeriya, kuma tana kai rahoton ayyukanta ga ofishin hukumar NSA. Babban nauyin da ya rataya a wuyanta shi ne a cikin kasar kuma ya hada da yaki da leken asiri, tsaro na cikin gida, yaki da ta'addanci, da sa ido da kuma binciken wasu nau'ikan manyan laifuka da ake yiwa jihar. Ana kuma dorawa alhakin kare manyan jami’an gwamnati, musamman shugaban kasa, mataimakin shugaban kasa, gwamnonin jahohi da shugabannin jihohi da gwamnatocin da suka kai ziyara tare da iyalansu. hedikwatar ta a Abuja . Kamar yadda shelar shugaban kasa ta 1999 ta nuna, hukumar SSS tana aiki ne a matsayin sashe a cikin ma’aikatar tsaro da kuma karkashinta mai baiwa shugaban kasa shawara kan harkokin tsaro .