Sensory integration (SI) is a complex process, the theory of which is based on a number of studies in the field of neuroscience. The greatest contribution to the development of this theory has Dr. A. Jean Ayres, who began her research on the subject back in 1950. SI can be defined as an effective interaction between man and the ever-changing environment that is based on the successful interpretation of sensory impressions. These impressions come into the nervous system in the form of information from sensory systems (visual, auditory, olfactory, taste, tactile, proprioceptive, vestibular and interoceptive). There the information is processed and arranged, and as a result the nervous system is ready to answer. This response is called an adaptive response and helps the individual to succeed successfully in terms of his/hers inner sensation, movement, emotions and behavior. When the SI process is disturbed at one of its stages, making an adaptive response is difficult. This condition is called sensory integrative dysfunction (SID) or also sensory processing disorder (SPD). Clinically sensory integrative dysfunctions may be related to manifestations of delayed psycho-motor development in the child, emotional imbalance, behavioral problems and difficulties in learning, communication and social skills. Signs of SID are most common in the following conditions: high-risk infants; autistic spectrum disorders; attention-deficit/hyperactivity disorder (ADHD); fragile X syndrome; children with learning disabilities; brain damage; some genetic syndromes and others. The aim of the present study is to highlight the importance of building a good SI in every child and the need to carry out prevention and early intervention at the first signs of SID. The tasks of the study are: 1) to track the main stages of SI development during the first seven years of child's life; 2) to differentiate the main types of difficulty with regard to sensory processing; 3) describe the main symptoms of SID typical of the relevant age groups; 4) to offer some validated methods and tests for assessment of the condition; 5) give guidance on the therapeutic approach. This study is aimed at parents, teachers, medical and non-medical specialists working within or outside the nosological unit. It aims not only to help them recognize and understand the signs of SID, but also to guide them: how to support the specific needs of children through their personal and professional competencies and when it is necessary to redirect them to a specialized sensory integrative therapy (SIT). There is a number of scientific evidence that therapeutic interventions at the age of three years in children with different development deficits are more successful. Understanding children with SID, timely and accurate assessment, and appropriate therapy, would help improve their condition and prevent future complications.