Background – Tympanic membrane play an important role in the conduction of sound through middle ear. Its perforation cause hearing loss of varying degree on the basis of size of perforation. Aim & objective – To evaluate and analyse the degree of deafness in tympanic membrane perforation on the basis of size of perforation. Method – a prospective cross-sectional study was done on 80 patients of both the sex, with dry tympanic membrane perforation along with reduced hearing.Size of tympanic membrane perforation was evaluated under operating microscope. Patients were divided into three groups according to size of perforation; Group I (small), Group II (medium), Group III (large). Hearing loss was measured in each case with tuning fork test and pure tone audiometry. Result – Out of 80 patients 47% had small perforation, 34% had medium perforation and 19% had large tympanic membrane perforation. Deafness increased as the perforation size increased. [I vs. II (p < 0.001), I vs. III (p < 0.001) and II vs. III (p < 0.001) Conclusion – There is a strong association between size of tympanic membrane perforation and degree of deafness as deafness increase with size of perforation increase. Key words– Perforation, Deafness (Hearing loss), Tympanic membrane.