As a leader, which is most important to your organization—mission, core values or vision?

Agree with you Emad, a mission statement may be a start, with something to work with to achieve. The mission statement where I currently work is "printing is personal " we make every effort to ensure we produce a product that meets standards such as iso9001 only using paper made from trees grown in sfc agreditation. etc.

You cannot separate those three elements, they are complimentary to each other and integrated.

Without a vision there will be no core values, without core values you will not realize the organization-mission. In other words.....

"A leader is one who knows the way, goes the way, and shows the way" - John C. Maxwell