Changes in vocal patterns after adenotonsillectomy are questionable. Few articles had assessed acoustic changes in the voice of children pre and post adenotonsillectomy. The objective of the current study was to evaluate the effect of removal of hypertrophied tonsil and adenoid on the voice of children. prospective study tertiary care hospital (Minia university hospital) The study included fifty children ranging in age between 4 and 12 years, with adenotonsillar hypertrophy, indicated for adenotonsillectomy. Auditory perceptual assessment of speech included nasality, degree of hyponasality, degree of open nasality, and degree of dysphonia. Acoustic analysis of voice was done pre, one month and three months’ post adenotonsillectomy, using multidimensional voice program software (MVDP). Acoustic parameters- fundamental frequency (Hz), shimmer (dB), jitter (%), and noise- harmony ratio (NHR; dB) were analyzed. Our results reveal that there is statistical significance in FO, Jitters, Shimmer between preoperative and postoperative results and improvement continues even after three months postoperatively there’s no statistical significance regarding HNR preoperative and post-operative. There is weak statistical significant in correlation between HNR and APA of Voice and APA of speech after one month postoperatively as (P=0.047) Hypertrophied tonsil and Adenoid can lead to Hyponasal speech and/ or dysphonia this can be improved after their removal, so voice and speech changes that results from enlarged tonsil and Adenoid can be considered as indication of adenotosillectomy.