Purpose To assess phacoemulsification learning curve by analysing residents' surgical completion and complication rates. Methods This prospective study included 226 cases of phacoemulsification performed by 11 senior residents under a single supervisor during a 27-month period. Both completion and complication rates were collected to assess their surgical results. 'Short-term completion rate (STCR)', the frequency of the surgeries completed exclusively by the residents during every five consecutive cases, was used in the evaluation of the learning curve parameter. Results These residents could complete phacoemulsification independently in 101 surgeries (44.7%). Intraoperative complications occurred in 62 cases (27.4%), of which 11 cases were complicated with vitreous loss (4.9%). By tracing different residents' individual STCRs, we found that the learning curve for phacoemulsification surgery to be of an exponential pattern, and the first STCR of 60% to be a good representation of the exponential point. Before the residents' first STCR of 60%, their average completion rate was only 16.7% and complication rate was as high as 39.2%. While after that point, the average completion rate accelerated to 76.4% and complication rate decreased to 14.2%. Conclusion The learning curve of phacoemulsification is of an exponential pattern and the trainees' STCR can be a useful parameter to evaluate their surgical performance.