Abstract   Aim To evaluate the different types of meatoplasty procedures and size of meatoplasty in canal wall down mastoidectomy (CWD) with tympanoplasty and to recommend the adequate I size of meatoplasty for proper aeration and drainage of mastoid cavity.   Methodology A prospective and retrospective observational study was conducted from 1 May 2012 to 30 * April 2013 at the Dept of ENT and Head & Neck Surgery, at a tertiary care institute All 48 patients having squamosal type CSOM, in the Age range of 12 to 50 years was selected. Four different groups were made with 12 cases each having similar age range and sex composition. Standard surgical procedure for CWD mastoidectomy with tympanoplasty by a single senior surgeon was perform with four different techniques of meatoplasty namely Korner's flap, Siebenmann's flap, Mawson's flap and Bhatia et al's flap. Each patient were follow up at 3weeks, 6 weeks, 3month, 6 month and one year after surgery for reassessment. One way ANOVA and students' paired 't' were used for comparison of results   Result The mean size of Conchomeatoplasty in our study group was 1.59 cm. The mean decrease in the diameter of the conchomeatoplasty at the 3 month post operative follow up was 3mm (18.8%). The mean volume of mastoid cavity at the end of surgery was 4.37 ml. The mean reduction in the volume at end of 3 months after surgery was 0.81 ml.   Conclusion: Conchomeatoplasty is an essential part of canal wall down mastoidectomy procedure. It provides a channel for the epithelialisation of the raw post operative mastoid cavity, drainage of secretions, aeration of the entire cavity and post operative care. Adequate meatoplasty means that it should be large enough to cater to the needs of post operative cavity which has a much larger volume than the space that is normally exposed to the natural meatus.