Objectives: To explore the relationships between patient acuity, perceived and actual throughput times, and emergency department (ED) patient satisfaction. The authors hypothesized that high-acuity patients would be the most satisfied with their throughput times, as well as the overall ED visit. The authors also expected overall ED satisfaction to be more strongly associated with perceived throughput times compared with actual throughput times, regardless of acuity. Methods: This was a prospective survey of 1,865 ED patients at a large, inner-city hospital during a one-month period. Data were collected on patient demographics, acuity of patient illness, actual waiting time for evaluation by a physician, and actual overall length of stay. Patient satisfaction with various throughput times (i.e., perceived throughput time) and overall ED visit was assessed by using a seven-point scale (1 = poor, 7 = excellent). Analysis of variance, analysis of covariance (ANCOVA), and correlations were conducted to explore the hypotheses. Results: Patients with “emergent” acuity perceived their throughput times more favorably and were more satisfied with their overall ED visit compared with “urgent” and “routine” patients (all p < 0.01). Once the effects of perceived throughput time were controlled for by using an ANCOVA, acuity no longer predicted overall ED satisfaction. Correlations showed that overall ED satisfaction was more closely linked to perceived throughput times than to actual throughput times (average r= 0.62 vs. −0.12). Conclusions:“Emergent” patients are more satisfied than “urgent” and “routine” patients with their ED visits. “Emergent” patients perceived their throughput times more favorably than other patients, especially their wait for physician evaluation. Changing perceptions of throughput times may yield larger improvements in satisfaction than decreasing actual throughput times, regardless of patient acuity.