Abstract Amenity trees, defined as all trees excluding those in Forestry Commission and grant-aided woodlands, worked coppice, commercial orchards and hardy-stock nurseries, were surveyed in the Lothian Region between 1972 and 1975. The Region ( c. 188,000 ha or 1,877 km 2) was stratified into three land categories-(i) burghs (Scottish equivalent of English boroughs), (ii) lowland rural and (iii) upland rural, parts of at least 10% of the 1 km squares ( vide Ordnance Survey maps) of each land category being surveyed; the surveyed squares were selected randomly. Numbers of trees per ha ranged from 59 in burghs to 43 and 24 in lowland and upland (above 150m) rural areas respectively. In total there were 6·7 ± 1·9 million amenity trees in the Region divided as follows: 1·4 ± 0·4, 3·2 ± 0·9 and 2·1 ± 0·6 millions between the burghs and lowland and upland rural areas respectively; c. 1·0 m of the 1·4 million trees in burghs were located in Edinburgh. Approximately 70% of trees were deciduous with a larger proportion of conifers in upland areas than elsewhere; sycamore ( Acer pseudoplatanus L.), hawthorn ( Crataegus spp.) and Scots pine ( Pinus sylvestris L.) were the commonest of 76 species or generic groupings recorded, accounting for 11·6, 11·1 and 10·5% respectively of the regional total. Birch ( Betula spp.) was the commonest deciduous tree in upland areas where ash ( Fraxinus excelsior L.) and beech ( Fagus sylvatica L.) were more abundant than sycamore. In the burghs wych elm ( Ulmus glabra Huds.) was more numerous than hawthorn and less than sycamore. Trees in Edinburgh differed greatly from those in the smaller towns (burghs) with more rural atmospheres, where sycamore, wych elm, hawthorn, elder and birch contrasted with apple, lilac, flowering cherry, sycamore and rowan occurring abundantly in Edinburgh. Excluding Edinburgh, over 50% of the Region's trees were identified in broadleaved (26·7%), coniferous (21·4%) and mixed (13·6%) woodlands, with 12·0% and 8·1% occurring in shelterbelts and hedgerows respectively; gardens and parks, of all sorts, only accounted for 4·5% and 1·1% respectively. Size class distribution ssuggest that there are sufficient developing saplings to maintain the existing number of mature trees but that wych elm ( Ulmus glabra Huds.), unless devastated by Dutch elm disease, sycamore and ash are likely to increase at the expense of oak ( Quercus spp.), lime ( Tilia spp.), Scots pine and beech. In some situations, however, the resourse seems to be seriously deficient in saplings, e.g. oaks in parks.