Purpose: To compare the efficacy of an intracameralmydriatic agent with a topicalmydriatic eye drop during phacoemulsification cataract surgery.Methods: All the patients with age group between 40 to 80 years with immature senile cataract, who came to the Ophthalmology OPD & were posted for surgery, were randomized into two groups. One group received topical mydriatics (Group-A) & the other group received intracameralmydriatic (Group-B), for pupil dilation prior to surgery. Parameters compared among both the groups,werethe size of pupilat different time points during the surgery;the onset of action of mydriasis& mean changes of variation in the pulse rate, systolic & diastolic blood pressures, at various time points during the surgery.Result: A total of 204 patients were enrolled in this study, who were randomly divided among both the groups (102 each). In Group-A, it was observed that the mean pupil size was maximum at 30 minutes after the start of topical drug administration i.e.- (7.81 +/-1.03) mm.; which gradually decreased towards the end of surgery. Whereas, in Group-B, the pupil size measured during the same time was (7.45 +/-0.81) mm., which also decreased gradually towards the end of surgery. But, following nucleus removalfrom the anterior chamber &corticalaspiration, the mean pupil size in Group-B was observed to be (6.45 +/-0.91) mm., which was greater than that of Group-A, i.e.- (6.01 +/-0.70)mm. Also, the time duration for which the pupil was larger during the surgery was found to be better in Group-B, compared to Group-A. Moreover, blood pressure & pulse rate, measured during various time points during the surgery, were observed to be within the permissible limits in both the groups.Conclusion: Intracameralmydriasis is a rapid, safe & effective alternative for pupil dilatation, during cataract surgery, with lesser systemic side effects; compared to the traditional topical eye drops.