Abstract Children with hearing disorders face particular challenges in developing their vocabulary. They often have difficulty in acquiring spoken language at the same rate as their normal hearing peers, despite progress regarding hearing aid technology.Aim. The main aim of this study was to describe aspects of expressive vocabulary for school-age children with mild to moderately severe hearing impairment (HI-group), and to compare with results for a group of normal hearing children (NH-group) of the same age. One aim was also to test whether there were differences, between children with hearing impairment and normal hearing children, in the ability to repeat non-words and sentences and to compare these results within each group with results on two newly constructed vocabulary tests. An additional aim was also to investigate whether background factors, such as age of diagnosis, age of hearing aid fitting and amount of hearing aid use, were related to results on vocabulary tests.Method: 24 children age 7-11 with mild to moderately severe bilateral hearing impairment, and 82 normal hearing children of similar age, were included in this cross-sectional study. Assessments of picture naming, word definition, repetition of nonwords and repetition of sentences were performed with all participants. Age, hearing, use of hearing aid and parents' level of education were included in the analyzes.Results: The HI-group performed significantly below the results of the NH-group regarding picture naming, word definition, nonword repetition and repetition of sentences. The HI-group also produced significantly more words with deficiencies in phonological structure, than the NH-group, during picture naming. In the HI-group there was a significant positive correlation between amount of hearing aid use per day and nonword repetition. Age of diagnose and age of hearing aid fitting did not show statistically significant associations with outcomes on the language tests in this study.Conclusion: Despite the technical development of hearing aids, the expressive vocabulary in school-aged children with bilateral, mild to moderately severe, hearing impairment, does not reach the same level as in normal-hearing peers, although there is a variation within the group. Amount of hearing aid use seems to be important for the ability to perceive new words.