The Illinois soil N test (ISNT) has shown promise as a tool to adjust fertilizer N rate recommendations to account for soil N mineralization potential. We determined the relationship between ISNT and corn response to fertilizer N in 16 N-response trials in the Coastal Plain (n=15) and the Shenendoah Valley (n=1).  Locations had a history of continuous no-till ranging from 3 to 25 years.  Three of the Coastal Plain sites received biosolids within the last 5 years. The Shenandoah location regularly receives dairy manure. The experimental design at all locations was a randomized complete block with 4 replications. Starter N fertilizer was applied at rates ranging from 0 to 67 kg N ha^-1. Eight sidedress N treatments were applied at growth stage V6 as UAN solution at 0 to 210 kg N ha^-1. Soil samples collected from 0 – 15 cm prior to planting were analyzed for ISNT-N and KCl extractable [NH₄+NO₃]-N. We found a negative correlation between ISNT and yield response to sidedress N, though the relationship was weak (r²=0.24). We also found a negative relationship between ISNT and the kg N kg^-1 grain at the economically optimum N rate (r²=0.38).  This relationship may be especially useful if the ISNT is used to augment the current Virginia recommendations based on expected yield. Results from the 16 N-trials conducted during the 2006 growing season indicate the assay has potential to be a useful tool to adjust fertilizer N rates were management practices have altered the quantity and cycling of soil organic N. More trials are needed to determine if the relationship is strong enough to be used for adjusting N fertilizer needs. Our evaluation of the ISNT is continuing with several more N trials (15 to 20) conducted in the 2007 growing season.