Now, I would like to turn the call over to the Chief Financial Officer of BBSI, Mr. Jim Miller. Please go ahead, sir.
Thank you, Marisa. And depending upon where you are dialing in from, good morning or afternoon, everyone. As you saw at the close of the market yesterday, we issued a press release announcing our financial results for the first quarter ended March 31, 2012. I would like to mention that yesterday’s earnings release summarizes our revenues and cost of revenues on a net revenue basis as required by generally accepted accounting principles, or GAAP.
Most of our comments today, however, will be based upon gross revenues and various relationships to gross revenues because we believe such information is, one, more informative as to the level of our business activity; two, more useful in managing and analyzing our operations; and three, adds more transparency to the trends within our business. Comments related to gross revenues as compared to a net revenue basis of reporting have no effect on gross margin dollars, SG&A expenses or net income.
Now turning to the first quarter results, total gross revenues increased 31% to $432 million, compared to the first quarter of 2011. California, which comprised approximately 86% of our overall first quarter gross revenues, increased 35% due to continued growth in PEO business. PEO gross revenues increased 34% to $406 million, compared to the first quarter of last year, primarily due to new clients as PEO business from new customers during the first quarter of 2012 more than tripled our lost PEO business from former customers as compared to the 2011 first quarter. Our PEO revenues from existing customers experienced approximately a 10% increase year-over-year.
Staffing revenues for the first quarter of 2012 decreased 7% to $26 million, compared to the first quarter of 2011, primarily due to a small decline in revenues of lost business from former customers, partially offset by new business and a slight increase in revenues from existing customers.