Second quarter 2011 advertising sales declined 16.7%, compared to a second quarter of 2010 decline of 16.4%. Adjusted earnings before interest, taxes, depreciation and amortization were $152 million for the second quarter of 2011, a 7.9% decline compared to second quarter of 2010 adjusted pro forma EBITDA of $165 million.
Cost management and expense reductions partially mitigated revenue declines, resulting in an improved adjusted EBITDA margin of 36.1% compared to an adjusted pro forma EBITDA margin of 32.2% in the second quarter of 2010. As I have mentioned on prior calls, we have been applying strong financial discipline in our cost structure. During the second quarter, we continued addressing costs, efficiencies and processes, reflected in our ability to maintain the margin improvement we saw in the first quarter.
Before Dee speaks about our financials, let me briefly provide an update on our Q2 activities, just some of the challenges facing small businesses, and outline our go-to market approaches. During the second quarter, we continue improvements to become local media advisers for small businesses, and we did this in a number of ways. First, based on the results of face-to-face research with local businesses across the country, we simplified our existing product offerings and pricing. We also introduced solutions providing mobile websites, and management of Facebook business pages and other social media. Second, to strengthen the trusted relationships with clients, we restructured our sales channels, closing our centralized national telephone call center and moving these customers to the existing media consultants in our local offices. Third, we continue to evaluate, and eliminate products and markets that fell short of our criteria for substantial profitability. While these decisions were difficult, they were necessary to focus on profitability. Fourth, we implemented, streamlined and simplified operational processes to improve service quality, reduce administration, and allow our sales force to spend more time with customers.