Introduction: Emergency Department (ED) overcrowding has been shown to delay time sensitive tests and therapies. North American guidelines call for Door-to ECG (DTE) times to be <10min in patients presenting with chest pain as delays have been shown to lead to poorer patient outcomes. We hypothesize that increased ED crowding will increase the DTE times. Methods: This was a retrospective cohort study from July 2015-May 2016 at a single tertiary care Canadian ED (53000 visits per year). Data were extracted from the ED information system (EDIS) which contains an organized record of ED activity for each visit. Our selection criteria screened for patients presenting with complaints that included chest pain, chest heaviness, chest tightness and chest burning. The primary outcome of the study was the association between ED occupancy and DTE time, which was measured using a non-parametric Spearman correlation. Multivariable linear regression models controlling for age and sex were developed for both time in minutes, and the log transformed time in minutes. Results: There were 2479 ECGs done on patients presenting with chest pain that met inclusion criteria. The median DTE time was 55.1 minutes. There was a significant positive association between DTE time and ED occupancy (rho=.133, p<0.001). DTE time increased by 0.64 minutes (or approximately 0.4%) for each additional patient in the ED, p<0.001. Additionally, younger age and female sex were also associated with increased DTE time. Conclusion: Increased ED occupancy was correlated with longer DTE times at a single Canadian ED, even after controlling for age and sex. This study provides an example of the negative consequences of ED overcrowding.