Aim: The effects of sensorineural hearing loss (SNHL) are often complicated by additional disabilities, but the epidemiology of associated disorders is not clearly defined. The aim of this study was to evaluate the frequency and type of additional neurodevelopmental disabilities in a sample of children with SNHL and to investigate the relation between these additional disabilities and the aetiology of deafness. Method: One hundred children with severe/profound SNHL (60 males, 40 females; mean age 5y 7mo, SD 3y 6mo, range 8mo-16y) were investigated using a diagnostic protocol including neurodevelopmental, genetic, neurometabolic, and brain magnetic resonance imaging (MRI) assessment. Results: Forty-eight per cent of the sample exhibited one or more additional disabilities, with cognitive, behavioural-emotional, and motor disorders being the most frequent. The risk of additional disabilities varied according to the type of aetiology. Thirty-seven out of 80 individuals with available MRIs showed signal abnormalities, in particular brain malformations (46%) and white matter abnormalities (54%). Frequency and type of disability were associated with aetiology (p = 0.015) and MRI data (p less than 0.001). Interpretation: A multidimensional evaluation, including aetiological, neurodevelopmental, and MRI investigation, is needed for planning therapeutic intervention, such as cochlear implantation in children with severe to profound hearing impairment. The aetiology of deafness is a relevant risk indicator for the presence of an associated disorder.