Giving zakaah to an organization so that they will distribute the zakaah to the needy
Question

                Is it permissible to give our zakat to the known organization which receive zakat to help the needy people without knowing where they are going to spend ?
Praise be to Allah.If you take 
      of it yourself and give it directly to one who is entitled to it according 
      to your understanding, then you will be sure that it has gone to the right 
      place. If you agree to give it to someone whom you trust to dispose of it 
      in the manner prescribed in Islam, this is also permissible.
Fataawa 
    al-Lajnah al-Daa’imah, 9/457
Shaykh Ibn Baaz said: If 
    the people who are doing that are trustworthy and honest, and will dispose 
    of the zakaah in the ways prescribed in sharee’ah, then it is OK to give 
    one’s zakaah to them, because this is a way of co-operating in righteousness 
    and piety.
Fataawa 
    al-Shaykh ‘Abd al-‘Azeez ibn Baaz, 3/126 .