Students attending public, private, or home school anywhere in the eastern half of Iowa, within roughly 150 miles of Cedar Rapids, are eligible to participate in the EISEF.  EISEF's eastern boundary is the Mississippi River;  the western boundary is just west of Mason City, Marshalltown, and Ottumwa, but east of Ames, Newton, and Pella.  Specifically schools in the following counties are assigned to EISEF:

The South Central Iowa Science and Engineering Fair (SCISEF) in Indianola covers the schools and students in Iowa west of EISEF's territory.  This year's SCISEF is scheduled for date to be determined.  For more information, visit the ISEF Affiliated Fairs (Iowa) page.

The State Science and Technology Fair of Iowa (SSTFI) in Ames is a "State Fair" and all students in Iowa may participate in that fair as well as their regional fair.  This year's SSTFI is scheduled for March 27–28, 2009.

Regional and State Fair assignments are made by Science Service, Inc., the organizers of the International Science and Engineering Fair.  For more information, visit the ISEF Affiliated Fairs page.

The top two winners from each regional and state fair may go on to the International Fair held each May.  EISEF can send up to two winners to the International Fair.