Abstract Introduction Emergency Department (ED) healthcare workers (HCWs) may be at elevated risk for the development of cardiovascular disease (CVD), due in part to sleep and/or circadian disturbances. This study aimed to evaluate the relationship of sleep factors with blood pressure, a primary marker of CVD risk, in ED HCWs. Methods Participants were HCWs (physicians, nurses, advanced practice providers, technicians, etc.) from 4 EDs in New York City who completed study procedures between November 2020-October 2021. Participants completed a 2-week data burst, which included sleep/activity (Fitbit Inspire) and home blood pressure monitoring (Omron 5 Series BP7250; preceding and following their main daily sleep episode). Linear regression models, adjusted for age, gender, and race/ethnicity, were conducted predicting blood pressure from sleep factors. Results The sample included n=74 ED HCWs (mean [SD] age=38.4 [8.7] years). Most were female (62.2%) and non-Hispanic/Latino White (55.6%). Mean systolic blood pressure (SBP) and diastolic blood pressure (DBP) were 116.1 (12.5) mmHg and 75.1 (7.6) mmHg, respectively. Actigraphy-derived sleep factor means for the data burst period were: a) Total sleep time (TST): 6.8 (1.0) hours; b) Sleep efficiency (SE): 94.5 (2.2)%; c) Percentage of main sleep episodes throughout the burst with TST <6 hours: 25.9 (20.8)%; d) Sleep start time: 24:06 (01:24); and e) Within-subject inter-daily bedtime variability (i.e., SD of sleep start times): 2.4 (1.8) hours. Higher TST was associated with lower SBP (B [SE] =-0.50 [0.30] mmHg/10 min, p=.04) and DBP (B [SE] =-0.50 [0.20] mmHg/10 min, p=.01). Greater SE was associated with lower SBP (B [SE] =-1.23 [0.55], mmHg/%, p=.03) and DBP (B [SE] =-1.05 [0.39], mmHg/%, p=.01). A higher proportion of nights with TST <6 hours was associated with higher DBP (B [SE] =1.4 [0.40], mmHg/10%, p<0.01) but not SBP. Sleep start time and bedtime variability were not associated with BP. Conclusion These findings provide support for the relationship between sleep and blood pressure. Of note, data were collected during the COVID-19 pandemic, which may impact observed relationships. Because this is a cross-sectional analysis, the causal direction of the association may be (at least partially) reversed. Further research should examine psychological and work-related factors in ED HCWs that may modify these relationships, e.g., stress/anxiety, burnout, and job strain, and include assessments of the circadian system. Support (If Any) R01HL146911