Prevalence data are of interest to health professionals and educators to assist in the planning of service delivery, allow for the calculation of the level of impact of intervention, and allow for the consideration of the boundaries between typical development and impairment. To determine the prevalence of children with communication disorders and other learning needs as identified by their teachers within all primary and secondary schools in an Australian school district over a 3-year period. Children with learning needs were identified from 14,514 students in the first year (wave 1) and the 14,533 students 2 years later (wave 2). Children were identified via a four-phased data-collection process designed to reduce selection and misclassification bias. Identification included teacher training, teacher referral, confirmation by documentation from relevant professionals including speech and language therapists, audiologists, psychologists and doctors, and verification by the school district learning needs advisors. Overall 5309 students were identified as having some area of learning need in the first year and 4845 students were identified 2 years later. In order of prevalence, the areas of learning need were: specific learning difficulty (17.93% in wave 1; 19.10% in wave 2), communication disorder (13.04%; 12.40%), English as a second or other language (9.16%; 5.80%), behavioural/emotional difficulty (8.16%; 6.10%), early achiever/advanced learner (7.30%; 5.50%), physical/medical disability (1.52%; 1.40%), intellectual disability (1.38%; 1.20%), hearing impairment (0.96%; 0.80%), and visual impairment (0.16%; 0.30%). The male:female ratio for all children was 1.57:1 (wave 1) and 1.66:1 (wave 2) and was the highest for the categories of behavioural/emotional difficulty, communication disorders. There were significant differences between learning need and socio-economic status quantile for all areas except early achievers/advanced learners and physical/medical disability. There was a higher prevalence of behavioural/emotional difficulty, and intellectual disability, in the lower socio-economic status quantiles and a higher prevalence of communication disorders in the mid-to-high socio-economic status quantiles. More children were identified as having an additional learning need in grades 1-3 (5-9 years of age). The children who were perceived as requiring the highest level of teacher support were those with an intellectual disability. This study provides comparative prevalence data for children with additional learning needs. There was a high prevalence of children typically seen in the caseloads of speech and language therapists, and teachers identified that many of these children required high levels of support within the classroom.