Dental mesowear and microwear are used to determine diet in the palaeothere Plagiolophus minor from a sequence of four localities across the Eocene—Oligocene transition in Europe: La Débruge, Soumailles, and Ronzon in France, and Frohnstetten in Germany. Plagiolophus minor was the only member of its family to survive more than fleetingly the mammalian faunal turnover, the Grande Coupure, which occurred during the earliest Oligocene in Europe. P. minor has a browsing diet at all the localities studied, but shows changes in the proportion of fruit and abrasive material. There is a decrease in the proportion of fruit between La Débruge and Frohnstetten (before the Grande Coupure) and an increase in the proportion of abrasive leaves across the Grande Coupure. There are two steps in increasing abrasiveness, one before the Grande Coupure and one across the Grande Coupure. The increase in abrasiveness across the Grande Coupure coincides with the timing of the Oi-1 glaciation. After the Grande Coupure, there is no change in diet for the first ∼0.3 Ma.