Consent of Independent Certified Public Accountants
We have issued our report dated June 16, 2000 accompanying the financial
statements of Van Kampen Merritt Insured Income Trust, Series 20 as of April 30,
2000, and for the period then ended, contained in this Post-Effective Amendment
No. 8 to Form S-6.
We consent to the use of the aforementioned report in the Post-Effective
Amendment and to the use of our name as it appears under the caption "Auditors".
Grant Thornton LLP
Chicago, Illinois
August 25, 2000
