The examinations were performed before and one month after adenoidectomy Comparison of the obtained results did not show significant changes in gasometric results due to operation. No correlation also was shown between the weight of the adenoid and changes in gasometric parameters after operation. In all children the improvement in clinical stage after operation was observed. Based on obtained results it seems that about nasopharyngeal obstruction in children with enlarged adenoid decides not its weight (size) only but the ratio between its size and nasopharyngeal capacity.