Life cycle assessment (LCA) was used to compare the impacts of two adhesive systems used for medium density fiberboard. Adhesives made from a theoretical protein–lignin-composite and petrochemical feedstocks were investigated. The inventory data was obtained from published literature, site investigations and laboratory scale experiments. Ecoindicator 99, a single score sustainability impact assessment method was applied. Our calculations reveal that the bioadhesive composed only of bio-based ingredients has a 22 % lower life cycle impact than the adhesive from petrochemical origin. The principal impact on both petrochemical and bioadhesive manufacture comes from the use of local mineral resources and the bioadhesive shows a considerable decrease (39 %) in environmental impact scores compared to the petrochemical adhesive. Underlying issues in LCA methodology are discussed in relation to potential contribution to the value proposition and ingredient selection for emerging bioadhesives.