Background Higher numbers of registered nurses per patient have been associated with improved patient outcomes in acute care facilities. Variation and associations of patient-care staffing levels and hemodialysis facility characteristics have not been previously examined. Study Design Cross-sectional study using Poisson regression to examine associations betwee patient-care staffing levels and hemodialysis facility characteristics. Setting & Participants 4,800 U.S. hemodialysis facilities in the 2009 CMS ESRD Annual Facility Survey (CMS-2744), USRDS. Predictors Facility characteristics, including profit status, freestanding status, chain affiliatio and geographic region, adjusted for facility size, capacity, functional type, and urbanicity. Outcomes Patient care staffing levels, including ratios of Registered Nurses (RN), Licensed Practical Nurses (LPN), Patient Care Technicians (PCT), composite staff (RN+LPN+PCT), Social Workers, and Dietitians to in-center hemodialysis patients. Results After adjusting for background facility characteristics, the ratios of RNs and LPNs to patients were 35% (p<0.001) and 42% (p<0.001) lower, but the PCT-to-patient ratio was 16% (p<0.001) higher in for-profit facilities than those in nonprofit facilities (Rate ratio, 0.65, 95%CI, 0.63–0.68; 0.58, 0.51–0.65; 1.16, 1.12–1.19; respectively). Regionally, compared to the Northeast, the adjusted RN-to-patient ratio was 14% (p< 0.001) lower in the Midwest, 25% (p< 0.001) lower in the South, and 18% (p< 0.001) lower in the West. Even after additional adjustments, the large for-profit chains had significantly lower RN and LPN ratios than the largest nonprofit chain, but a significantly higher PCT-to-patient ratio. The overall composite staffing levels were also lower in for-profit and chain-affiliated facilities. The patterns hold when the hospital-based units were excluded. Limitations Nursing hours were not available. Conclusions The significant variation in patient-care staffing levels and its associations with facility characteristics warrants inclusion in future large-scale hemodialysis outcomes studies. ESRD networks and hemodialysis facilities should attend to quality assurance and performance improvement initiatives that maximize licensed nurse-staffing levels in hemodialysis facilities.