In Hungary the concept of developmental dysphasia joined to hearing impairment became known as a specific type of neuro-origin learning disorder that causes a serious language developmental handicap in a considerable part of hearing impaired children. Incidence is estimated 6-35%. Types of occurrence: with dominance of dyspraxia, sensory-motor-integrated dysphasia, mixed developmental dysphasia. The team of the Institute of Rehabilitation Psychology adapted the diagnostic method of A. M. J. Van Uden for exploration of developmental dysphasia. Early diagnosis of hearing impaired children with developmental dysphasia and the prosperous improvement of language is the primary condition of hearing impaired children's learning success and harmonic growing up. The case study describes the complex screening method through the case of a child with developmental mixed-type dysphasia.