In this descriptive study in 100 patient with ASA class I, II with age range between 18-65 years that were candidates for elective surgery on abdomen and lower limb to study the pressure transmitted by the laryngoscope blade on the base of the tongue and the relation between the laryngoscipic pressures and post-operative sore throat laryngoscopy was performed with a modified size 3 macintosh blade and a small ballon was attached to the tip of the blade that was connected with a narrow pipe to the pressure sensore of the monitor and calibrated before each measurement.In this study four different laryngoscopic parameters were determind:1) The duration of laryngoscopy; 2) The maximally applied pressure; 3) The mean pressure; 4) The surface area under the pressure time curve. Twenty four hours after the surgery, the intensity and frequency of sore thorat were measured by visual analyze scale (VAS). The data were analyzed by SPSS soft-ware and ANOVA; the discriminant was analyzed, the result was presented by Mean±SD. The result of this study demonstrates: 1) The duration of Laryngoscopy is 10.57±1.66 seconds; 2) The maximally applied pressure is 259.73±21.17 mmHg 3) The mean pressure is 156.30±19.00 mmHg 4) The surface area under the pressure-time curve is 2939.97±413.00 mm2.There was a positive correlation between maximum pressure and sore throat (P=0.001) and mean pressure and sore throat (P=0.006). Between post operative sorethroat and other factors such as age, sex, duration of laryngoscopy, duration of operation, and surface area under the pressure-time curve. There is no positive correlation. The findings show that post-operative sorethroat is related to maximum and mean laryngoscopic pressure. This fact has not been evaluated in previous researches.