BACKGROUND: CHILDREN WITH PROFOUND SENSORINEURAL HEARING LOSS ARE AT RISK OF LANGUAGE DELAYS THAT CAN IMPACT THEIR ACADEMIC AND SOCIAL DEVELOPMENT. A SUITABLE WAY TO DEVELOP THE SPEECH AND LANGUAGE OF DEAF CHILDREN IS COCHLEAR IMPLANTATION (CI). THE MAIN PROPOSE OF THIS STUDY IS THE EVALUATION OF THE CHILD'S DEVELOPMENT IN SUCH LANGUAGE SKILLS AS INFORMATION, SIMILARITIES, ARITHMETIC, VOCABULARY AND COMPREHENSION AFTER CI SURGERY AND REHABILITATION.METHODS AND MATERIALS: THE PRESENT STUDY IS A QUASI-EXPERIMENTAL STUDY. FOR THIS REASON, WE PERFORMED THE RAVEN TEST ON ALL THE CI CHILDREN OF THE FARS CI CENTER, WHO WERE AT LEAST 6 YEARS OLD AND HAD FINISHED THEIR REHABILITATION PROGRAM ABOUT THREE YEARS BEFORE. AFTER THAT, WE SELECTED 23 PATIENTS WHO HAD THE SELECTION CRITERIA FOR ANSWERING THE VERBAL PART OF WECHSLER INTELLIGENCE SCALE FOR CHILDREN III (WISC-III). FOR THE STATISTICAL ANALYSIS, WE USED THE SPSS SOFTWARE VERSION 11.5.RESULTS: THE VERBAL INTELLIGENCE QUOTIENT (IQ) DEVELOPS AFTER THE SURGERY AND REHABILITATION PROGRAM OF C.I. CHILDREN. HOWEVER, IT IS NOT THE SAME AS IN NORMAL CHILDREN OF THE SAME AGE. THE MOST IMPORTANT FACTORS THAT AFFECT THIS ARE THE CHILD'S AGE AND FAMILY EDUCATION. ALSO, THERE IS NO SIGNIFICANT RELATION BETWEEN VERBAL AND NON-VERBAL IQS.CONCLUSION: ALTHOUGH C.I. IS A SUITABLE WAY TO INCREASE THE VERBAL IQ AND COGNITIVE DEVELOPMENT, FOR BETTER RESULTS, IT IS RECOMMENDED IN CHILDREN UNDER THREE YEARS OF AGE.