The bean leaf beetle (BLB), Cerotoma trifurcata (Forster), is a major pest of snap beans in the eastern and central U.S. Adults feed on leaves and pods of soy beans, snap beans and other legumes. Research on economic injury levels for this pest has focused primarily on soybeans. In order to gain more insight into the impact of early-season BLB defoliation on snap beans we conducted field-cage and manual leaf-hole punch studies. Walk-in exclusion cages were used to house snap bean plants in the field containing 0, 1, 2, 3, 4 and 5 bean leaf beetles per plant in each of six cages. Foliar damage was assessed using a leaf area meter at 30 and 40 days post planting while whole-plant and pod yields were assessed at harvest. BLB density had a significant effect on defoliation and leaf area at 30 days after planting. However, leaf area data collected 40 days post planting showed no significant difference between cages. There was also no significant difference between whole-plant and pod weight. Manual leaf hole punch studies, which simmulated BLB feeding also revealed no significant effect of defoliation on snap bean yield. Based on these data, it appears that snap bean plants can overcome early-growth stage defoliation from BLB without significant loss in pod yield. This resilience to foliar injury in snap beans appears to be similar to that exhibited by soybeans, and thus BLB can probably be managed in both crops under comparable IPM guidelines.