OBJECTIVEThe objective of this study was to compare the outcomes of endoscopic cartilage underlay myringoplasty(CNM) with or without balloon Eustachian tuboplasty (BET) for the treatment of chronic perforation with Eustachian tube dysfunction (ETD).MATERIALS AND METHODSA total of 50 ears diagnosed with chronic perforation and ETD were randomly divided into receiving alone CNM and CNM + BET. During the 12 months follow-up, the Eustachian tube score (ETS), Eustachian Tube Dysfunction Questionnaire-7 (ETDQ-7), ET inflammation scale, hearing results and graft success rate of the patients were recorded and analyzed.RESULTSThe improvement in the ETDQ-7 score was 6.23 ± 2.51 in the CNM + BET group, which was significantly higher than that in the CNM group (4.22 ± 3.85, P < 0.01) at postoperative 3 months, however, no significant between-group difference was found at post-12 months.The graft success rate was 88.0 % in the CNM group and 92.0 % in the CNM + BET group at postoperative 3 months (P > 0.05). Also, no significant difference was found among two groups (84.0 % vs 88.0 %, P > 0.05).The ABG improvement was 13.16 ± 3.19 dB in the CNM + BET group and 9.74 ± 2.56 dB in the CNM group, with a statistically significant between-group difference (P < 0.01)at postoperative 3 months. However, no significant between-group difference was found at postoperative 12 months. During followup process, neither complications nor patulous symptoms were noted. No patients developted atelectasis or otitis media with effusion. However, myringitis was seen in 8 % patients in the CNM group and 12 % patients in the CNM + BET group.CONCLUSIONSAlthough BET combined with endoscopic cartilage myringoplasty had better short-term improvement of hearing and ETDQ-7 scores compared with endoscopic cartilage myringoplasty for the treatment of chronic large perforation with ETD, the long-term outcomes was not satisfactory. Also, BET did not improve the 3-and 12 months graft success rate.