The purpose of this study was to describe hearing aid fitting characteristics and the effects of fitting when using RECD in patients with a tympanic membrane (TM) perforation. 10 subjects with TM perforations and 8 subjects with intact TM participated in this study. RECDs were measured by using a real ear measurement system and used in fitting hearing aids through Speechmap program. Electroacoustic analysis including OSPL 90 and RESP 50 were performed in both Test-box and On-ear conditions. Aided sound field thresholds were also obtained in both conditions. There were no significant differences in hearing aid fitting characteristics and sound field aided thresholds in both Test-box and On-ear conditions for the intact TM group. However, significant differences were shown at lower frequencies below 1,000 Hz for the perforated ears in these conditions. Individual RECD is needed especially for patients with TM perforation because it can prevent from underamplification. These results suggest that individual RECD measurements are strongly recommended in fitting a hearing aid for its best outcome.