‘Zombie lending’ occurs when a lender supports an otherwise insolvent borrower. Recent studies document that zombie lending has been widespread following the European sovereign debt crisis. In this paper, I develop a quantitative model to study the impact of these lending practices on firm dynamics. In the model, firm liquidations and zombie lending arise endogenously. The model provides a good match to key euro‐area firm statistics over the period 2011–14. I find that zombie lending has a substantial impact on borrowing costs, helping more low‐productivity firms to survive. This, in turn, causes a drag on aggregate output, investment and productivity.