We studied changes in ground-level vegetation (shrubs, herbs, vines, trees) in a deciduous forest before (1984) and after (1987) the initial stages of a gypsy moth (Lymantria dispar) invasion. Seventeen of 18 plant species known to be important wildlife food plants increased in percent cover from 1984 to 1987. Total percent ground cover and plant species richness also increased. At the same time, the number of snags and snag basal area increased but not significantly, implying that the gypsy moth can be used as a management tool to enhance understory vegetation without harvesting trees. By 1988, however, tree mortality had significantly increased. A variety of options, therefore, exists for wildlife managers faced with a gypsy moth invasion, including no action, halting the outbreak with pesticides, or silvicultural treatment prior to invasion. Advantages and disadvantages of each depend on management objectives and budgetary and environmental constraints.