Visualize-HD study aimed to examine prevalence of hyperkalemia (HK), associated practice patterns, and mortality in Chinese patients undergoing hemodialysis (HD). The study included patients aged ≥ 18 years and undergoing chronic HD for ≥ 3 months. Primary outcome was to examine the association between suspected risk factors and HK prevalence at the HD facility level. Secondary outcomes were to determine the HK prevalence, management pattern of serum potassium (sK), and risk factors associated with crude mortality. Overall, 50,983 patients undergoing HD from 231 HD centers were enrolled. HK prevalence (sK > 5.0 mmol/L) in patients undergoing HD was 40.84%. Proportion of patients sK > 5.5, > 6.0, > 6.5 mmol/L was 20.42%, 8.7%, and 3.21%, respectively. Three-year cumulative mortality of patients undergoing HD was 21.3%. Notably,  36.7% of deceased patients had HK as indicated by their final sK test results. Facilities in high HK prevalence group had a higher all-cause and cardiovascular mortalities compared with low HK prevalence group (20.7% vs. 21.9% and 11.5% vs. 13.5%; P < 0.05). A higher prevalence of hyperphosphatemia [hazard ratio (HR) 1.04 (95% confidence interval (CI): 1.01-1.07)] and more usage of potassium-binding drugs [HR 1.04 (95% CI: 1.00-1.07)] were positively associated with higher HK prevalence for facilities, whereas hypoalbuminemia prevalence and more elderly patients were reversely associated with higher HK prevalence for facilities. HK is prevalent in Chinese HD centers and is associated with risk factors. Chinese HD centers with a higher HK prevalence had higher mortality rates. Although, long-term sK control is important for improving survival in patients undergoing MHD, potassium-binding drugs are underused.Clinical trial registration number: NCT05020717.