We will refer to a non-GAAP financial measure, adjusted diluted EPS attributable to Equifax, which excludes acquisition-related amortization expense. And the loss on the deconsolidation of Brazil in 2011. Since the Brazilian operations were merged with Boa Vista on May 31, 2011, we also present revenue growth excluding Brazil to provide a clearer understanding of our revenue growth for those businesses that will continue to be reported in our operating results.
These measures are detailed in our non-GAAP reconciliation tables included with earnings release and also posted on our website. Please refer to the non-GAAP reconciliation and our investor -- various investor presentations, which are posted in the Investor Relations section under the About Equifax tab on our website for further details.
Now I'd like to turn it over to Rick.
Richard F. SmithThanks, Jeff. Good morning, everyone. Thank you for joining us this morning. It's to be no surprise that we are quite pleased with our second quarter performance. We continue to execute well against our strategic initiatives, capturing available opportunities from a cyclically strong mortgage market while continuing to deliver solid non-mortgage organic growth that's consistent with our long-term business model. Shortly, we'll update you on our full year outlook. But first, let's take a quick look at high some high-level financials for the second quarter. Total revenue was $536 million, up 10% from the second quarter when you -- excluding Brazil. Total revenue was up 14% for the quarter and up 15% in constant dollars. Operating margin was 24.8%, up 130 basis points from a year ago and consistent with the model we have weighed out for you over the past few quarters. Finally, adjusted EPS was $0.74 a share, up 21% from $0.61 a year ago. Broad 2011 and the first half of 2012, we have delivered solid non-mortgage organic performance with little to no help from the macro economy in most of the developed parts of the world. What we've been doing is focusing relentlessly on executing our strategic objectives, attracting and developing a world-class management team and leveraging our fierce determination to drive innovation and growth across the enterprise.