I would now like to turn this call over to Peer.
Peer Schatz – Chief Executive Officer
Thank you, Al. I would like to welcome all of you to our conference call and the opportunity to discuss our results for the fourth quarter and full year 2011. As you saw in our release last night, we delivered dynamic growth in the fourth quarter. Net sales were up 17% at constant exchange rates to $334 million by adjusted net income rose 19% to $74 million and adjusted EPS came in at $0.31 per share.
The strong finish led to net sales growth of 4% in the constant exchange rate basis for the full year to $1.17 billion. An adjusted EPS for the full year rose to $0.98. We achieve these results, which were ahead of our goals against the backdrop of a challenging business environment when they did not improve during the course of the year.
The key driver has been our progress on four strategic initiatives. Number one, we are driving platform success, especially with the rollout of the breakthrough QIAsymphony automation platform. Number two, we are adding content across all of our customer classes. Number three, we are expanding our geographic presence especially in high growth markets. And number four; we are improving our efficiency and effectiveness. We are clearly not growing yet at a rate that we believe our company can deliver, but our strategic initiatives are on track to get there. And achieving these results in 2011 was an important step of course to accelerate full year sales growth to faster pace in 2012.
Moving to Slide 5, you can see that we achieved our goals deliver markedly improved year-on-year performance in the second half of 2011, compared to the first half. We had said previously that the second half of 2011, we provide a proxy as to how we believed growth could accelerate for the full year in 2011 and 2012.