Syntroleum (SYNM)

THIS PROXY IS SOLICITED ON BEHALF OF THE BOARD OF DIRECTORS

The undersigned hereby appoints Kenneth L. Agee, John B. Holmes, Jr. and Richard L. Edmonson, and each of them individually with the power of substitution, as Proxy or Proxies of the undersigned, to attend and act for and on behalf of the undersigned at the Annual Meeting of Stockholders of Syntroleum Corporation (the “Company”) to be held at Tulsa Community College, West Campus, 7505 West 41^st Street, Tulsa, Oklahoma 74107 on April 23, 2007 at 1:00 p.m. local time and at any adjournment thereof, hereby revoking any prior Proxy or Proxies. This Proxy when properly executed will be voted as directed on the reverse hereof by the undersigned. If no direction is made, shares will be voted “FOR” proposals 2 and “FOR” the election of directors named in the Proxy.

(Continued and to be signed on the reverse side)

THIS PROXY IS SOLICITED ON BEHALF OF THE BOARD OF DIRECTORS

The undersigned hereby appoints Kenneth L. Agee, John B. Holmes, Jr. and Richard L. Edmonson, and each of them individually with the power of substitution, as Proxy or Proxies of the undersigned, to attend and act for and on behalf of the undersigned at the Annual Meeting of Stockholders of Syntroleum Corporation (the “Company”) to be held at Tulsa Community College, West Campus, 7505 West 41^st Street, Tulsa, Oklahoma 74107 on April 24, 2006 at 3:00 p.m. local time and at any adjournment thereof, hereby revoking any prior Proxy or Proxies. This Proxy when properly executed will be voted as directed on the reverse hereof by the undersigned. If no direction is made, shares will be voted “FOR” proposals 2 and 3 and “FOR” the election of directors named in the Proxy.

(Continued and to be signed on the reverse side)

THIS PROXY IS SOLICITED ON BEHALF OF THE BOARD OF DIRECTORS

The undersigned hereby appoints Kenneth L. Agee, John B. Holmes, Jr. and Richard L. Edmonson, and each of them individually with the power of substitution, as Proxy or Proxies of the undersigned, to attend and act for and on behalf of the undersigned at the Annual Meeting of Stockholders of Syntroleum Corporation (the “Company”) to be held at Tulsa Community College, West Campus, 7505 West 41^st Street, Tulsa, Oklahoma 74107 on April 25, 2005 at 3:00 p.m. local time and at any adjournment thereof, hereby revoking any prior Proxy or Proxies. This Proxy when properly executed will be voted as directed on the reverse hereof by the undersigned. If no direction is made, shares will be voted “FOR” proposals 2, 3, and 4 and “FOR” the election of directors named in the Proxy.

(Continued and to be signed on the reverse side)