Introduction:  Patency of the eustachian tube has been proved to be mandatory for successful tympanoplasty. Preoperative evaluation of the eustachian tube through Saccharin and methylene blue tests provides adequate information about the mucociliary function and patency of the eustachian tube
Objective:  We aimed to evaluate the mucociliary function of the eustachian tube using saccharin and methylene blue tests, hence we could predict the outcome of tympanoplasty.
Patients and methods: This prospective study was done on 50 adult patients who were diagnosed as having unilateral tubotympanic type of chronic suppurative otitis media. All patients were subjected to preoperative evaluation of hearing and eustachian tube mucociliary function through saccharin and methylene blue dye clearance tests. Then, we correlated the results and the outcome of the surgery. 
Results:  According to our results, normal eustachian tube function (ETF) was found in 39 patients, while mild and gross dysfunction was found in eight and three patients respectively. The correlation between ETF and the outcome of tympanoplasty was proved to be statistically significant (P< 0.001), as 85.3% of patients with successful tympanoplasty had a normally functioning ET, while all of the patients with a gross dysfunction of ET had a failed surgery.
Conclusion:  We found that both tests could be a helpful tool to assess the mucociliary function and anatomical patency of the eustachian tube. While, the Saccharin test has the advantages of cost-effectiveness, avoiding the painting produced by the dye, and lacking the need for an endoscope.