Background: The purpose of this study was to compare phacoemulsification energy parameters during torsional phacoemulsification with or without the use of intelligent phacoemulsification (IP) software.,Methods: One hundred and twenty-eight eyes with nuclear grades ranging from 1 to 5 were enrolled in this randomized prospective study. Operated eyes were divided into two groups, ie, those operated on using IP software (Group 1, n = 67) and those operated on without IP software (Group 2, n = 61). The two groups were compared in terms of ultrasound energy level, ultrasound energy time, aspiration time, and amount of fluid used during surgery.,Results: Operated eyes were further grouped according to soft (grade 1 and 2, n = 37), medium (grade 3, n = 46), and hard (grade 4 and 5, n = 31) nuclear densities. Both the study and the control groups were similar in distribution of nuclear density ( P > 0.05). Cumulative dissipated energy was measured as 14.06 +/- 9.92 in Group 1 and 14.22 +/- 10.99 in Group 2 (P = 0.92). Total ultrasound time was 49 seconds in Group 1 and 52 seconds in Group 2 (P = 0.58). Although the torsional amplitude used was similar (P = 0.86) when IP was either on (71%) or off (68.4%), aspiration time was found to be 4 minutes 17 seconds in Group 1 (P = 0.86) and 5minutes and 17 seconds in Group 2 (P = 0.007). Total fluid used was measured as 91 cc (P = 0.86) in Group 1 and 109 cc (P = 0.02) in Group 2.,Conclusion: The new IP software did not cause a difference in ultrasound energy levels. However, the new software was found to be advantageous in regards to fluid use and aspiration time.