Assessment of outcome of hearing aid fitting in children should contain several dimensions: audibility, speech recognition, subjective benefit and speech production. Audibility may be determined by means of aided hearing thresholds or real-ear measurements. For determining speech recognition, methods different from those used for adult patients must he used, especially for children with congenital hearing loss. In these children the development of the spoken language and vocabulary has to be considered, especially when testing speech recognition but also with regard to speech production. Subjective assessment of benefit to a large extent has to rely on the assessment by parents and teachers for children younger than school age. However, several studies have shown that children from the age of around 7 years can usually produce reliable responses in this respect. Speech production has to be assessed in terms of intelligibility by others, who may or may not be used to the individual child's speech. Ideally, the outcome should be assessed repeatedly at suitable intervals in order to be able to follow the child's communicative development.