Raindrop impact is a major agent of soil erosion, and any reduction in its effectiveness reduces sediment production from burned watersheds. A chaparral soil treated with heat-shock fungi in three combinations was compared to sterile soil to test the ability of postfire heat-shock fungi to diminish raindrop impact erosion. Two to three times as much sediment was detached from sterile soil as from any of the three fungal treatments. A 1-month incubation period was sufficient to allow all fungal treatments to resist raindrop impact.