Since the data provided in the literature concerning unilateral hearing loss in children are still lacking, we decided to study a group of subjects suffering from unilateral sensorineural deafness that has developed during the first 12 years of life. One hundred and fifteen subjects out of 150 answered a questionnaire that intended to investigate at what age the disorder developed, how it was recognized, its possible causes and a subjective evaluation of the difficulties encountered because of the hearing deficiency. In a second stage of the research, more detailed case history data were obtained on 30 children who satisfied more stringent selection criteria. The same children were compared with a matched control group of 30 normal hearing subjects, on speech in noise recognition, and sound localization skills. Results were correlated with the academic and educational progress and case history data. Our results may demonstrate that unilateral deafness represents a far from negligible handicap concerning the child's learning and relationship with classmates and teachers, specially during compulsory school life.