Recently, data from several sources were compiled to determine the known distribution of the soybean cyst nematode (SCN) in Iowa. These data included results of analyses of more than 3,500 samples submitted to the Iowa State University (ISU) Plant Disease Clinic from 1994 to 1998 and nearly 400 samples collected from randomly selected sites in a survey conducted in Iowa from 1995 to 1996. Presently, SCN has been found in 85 of 99 Iowa counties. The counties where SCN has not yet been confirmed are located primarily in northeast and south central Iowa.