Background: Twice-weekly hemodialysis (HD) is prevalent in the developing countries and the clinical outcome of this population remains to be elucidated. Methods: Data were collected from Shanghai Renal Registry. 2,572 patients undergoing regular HD in Shanghai on January 2007 were enrolled into the cohort study with 2 years’ follow-up. Clinical and HD parameters obtained from the network were utilized to compare twice-weekly with thrice-weekly HD. Results: Compared with patients on thrice-weekly HD, the twice-weekly HD patients were significantly younger and had significantly longer HD session time, higher single-pool Kt/V (spKt/V) but shorter HD vintage (p < 0.001). Kaplan-Meier survival analysis indicated that the two groups had similar survival. Multivariate Cox regression analysis showed that age, body mass index, serum albumin and weekly Kt/V were predictors of patient mortality. Conclusions: The similar survival between twice-weekly HD and thrice-weekly HD is likely relating to patient selection; dialysis adequacy of twice-weekly HD remains to be elucidated.