Retinal detachment (RD) following cataract extraction is a serious and potentially sight-threatening complication that often necessitates further surgical intervention. Several of the risk factors for RD after cataract extraction have been reported in the literature. Since the overall rate of RD after extracapsular cataract extraction is comparatively low at 0.18 to 3.6 percent, large numbers of cases are required for accurate analysis of the association of potential risk factors and RD following cataract surgery. Two large-scaled studies were performed, one based on National Health Insurance data (NHI, 9388 patients collected from 1999 to 2001) and one based on a single medical center (VGHKS, 9184 patients collected from 2000 to 2010). In the NHI study, the cumulative 8-year RD rate was 2.31% for the full group, 3.28% in the male subgroup, and 1.52% in the female subgroup at the end of the follow-up period. Factors with significant effect on the risk of RD included being male, younger, increased axial length, and history of RD in the fellow eye. In the VGHKS study, the cumulative 7-year RD rate was 0.84 %. Age, axial length and post-operative Nd-YAG laser capsulotomy showed significant effect on the risk of pseudophakic retinal RD. Comparison between National Health Insurance and one single medical center will be discussed.