Forest edges are important features of wooded farmland. Their role for biodiversity was investigated using tree microhabitats (TMH) as an indirect indicator of forest biodiversity. Because they are managed more intensively, trees in the edges of fragmented temperate woodlands are likely to host more TMH than trees in their interior. In this study, we tested this hypothesis in relation to tree density, diameter, species composition and the structure and management of woodland edges. We selected 28 woodlands with edges differing by their structure and the adjacent fields. Eleven types of TMH were recorded in two transects set up in the edges and interior of the woodlands. TMH density was significantly higher in the woodland edges (4.67 ± 0.78 per 100 m2 area) than in the interior (1.86 ± 0.23 per 100 m2 area). Some TMH - patches of bark loss, cracks, sap runs and epiphytes – were significantly more abundant in the edges than in the interior. These results were accounted for by the convergence of several factors: (i) significantly higher tree density in woodland edges, (ii) a significantly higher proportion of TMH host trees in woodland edges, (iii) a larger tree diameter on average in woodland edges and, even in the same given size class, a higher frequency of TMH host trees, and (iv) greater abundance in woodland edges of tree species more likely to host TMH, even with small diameters. The positive relationship found between the height of the bottom of the crown and TMH abundance may have resulted from abiotic factors (micro-climatic conditions) related to long management rotations, but we did not demonstrate any direct effect of management practices. Given the large number of forest taxa, but also farmland taxa, that depend on TMH, woodland edges should be reconsidered as zones of high potential interest for forest biodiversity conservation.