The development of forest monitoring methods for the plantation eucalypt forests in Ethiopia is crucial as eucalypts play an important role in the country’s wood supply. We assessed the stand structure and estimated the total stem volume of a 30-year-old Eucalyptus globulus forest in the highlands (> 3000 m altitude) of northern Ethiopia. Census data were collected from 186 trees, of which 28 trees were destructively sampled. The forest stand density was 581 trees ha^-1, mean ± SD diameter at breast height was 21.2 ± 6.4 cm, and mean ± SD predicted tree height was 22.0 ± 4.2 m. The estimated stem volume was 269.7 m³ ha^-1. An allometric model to predict tree height was derived using the measured diameter at breast height of the sampled trees. Moreover, an allometric model was developed to estimate stem volume for standing trees in order to describe the relationship between the stem volume and diameter at breast height squared × tree height (incorporated as a compound variable), using data on 38 trees for which height could be measured reliably. The findings suggest that the diameter at breast height alone can be used to estimate stem volume, and thus may be useful for simple forest monitoring in the study region. This study is one of the few to assess the stand structure and stem volume of a high-altitude Eucalyptus plantation.