Background: The “true value” to a community hospital of achieving the Joint Commission Primary Stroke Center (PSC) designation is unknown. On 8/26/2010 St. Rose Dominican Hospitals Siena Campus became Clark County, Nevada’s, ninth PSC. For 3 years prior to becoming a PSC our local fire company (Henderson, NV) bypassed our hospital so that suspected acute stroke patients could be taken to a PSC. Furthermore, on 1/1/2010 a County mandate was passed designating transport of patients with suspected acute stroke to a PSC. During the period August 1, 2007 to August 25, 2010 stroke patients were admitted to our hospital but we were restricted from receiving suspected acute strokes from pre-hospital providers. Our aim was to determine the true value to a community hospital of achieving the Joint Commission PSC designation in the first six months of operation. Methods: Using the Horizon Performance Management™ database we categorized inpatient admissions into stroke ICD-9-CM (Group 1), closely-stroke-related ICD-9-CM (Group 2), and loosely-stroke-related ICD-9-CM diagnoses (Group 3). Percent change in admissions alone and as a function of total inpatient admissions, and percent change in average contribution margin ($US) [net revenue - variable costs] for the three stroke and stroke-related categories were analyzed. We compared data for the 6-month epoch 9/1/2010 - 2/28/2011 to the average data from the same 6-month epochs in 2007-8, 2008-9, 2009-10. Results: 45%, 31%, and 21% increases in admissions were observed for Groups 1, 2, and 3, respectively. Admissions, as a percentage of total inpatient admissions, increased 5.97%, 0.64%, and 2.18% in Groups 1, 2, and 3, respectively. For Groups 1 & 2 combined the increase was 3.55% and for all groups combined was 5.73%. The percent increase in average contribution margin was 90%, 22%, and 25% for Groups 1, 2, and 3, respectively. Conclusions: The present method was utilized to estimate the “true value” of the PSC designation to a community hospital. The present study indicates that stroke and stroke-related inpatient admissions increase, along with contribution margins, after PSC designation. Lesser increases in Groups 2 and 3 vs. Group 1 (stroke) likely represent the “halo effect”, reflecting an increase in admissions for conditions similar to stroke, but that are not stroke, transported to a hospital by virtue of being a PSC. Future analyses should focus on length of stay and outcome measures in community PSCs.