Purpose:To compare between continuous and pulsed ultrasound regarding the following points: the effective phaco time, the total surgery time, time used to remove nucleus and amount of fluid used in each technique.Patients and methods:The study was carried out on 106 eyes of 105 cases of cataract. Coaxial phacoemulsification was randomly done using the continuous mode in 51 cases (group A) and the pulse mode in 54 cases (group B). The two groups were subdivided according to nuclear density into: Nuclear grades I, II, III, IV, and V.Results:There was no statistically significant difference between Effective Phaco Time (EPT) except for grade V, Time of nucleus removal, Total time of the procedure, and Amount of fluid used during the procedure in both groups.Conclusions:It is recommended to use the pulse mode in cases of very hard nuclei of grade V.