American chestnut survival was studied in 15 mesic understory sites located in the former oak–chestnut forest region of the eastern United States. Mesic deep coves and northeasterly slopes studied had no or low chestnut survival. Several shallow coves, north to northwesterly slopes, and a large cove slope examined had good chestnut survival. Live chestnut to chestnut stump ratios of 1 or greater were found on these sites. High canopy-tree basal area was not always associated with low chestnut survival, and vice versa. For five mesic sites studied in more detail, high chestnut survival was associated with higher basal areas for understory species (> 2.5 cm dbh) and frequency and basal area of red maple. Chestnut blight incidence was low or zero at these sites. Mesic sites, especially shallow coves, with surviving chestnuts may have the greatest potential for chestnut growth and biocontrol of blight, if effective hypovirulence, blight resistance, and forest management measures are developed. Key words: chestnut blight, forest competition, hypovirulence, biocontrol.