Just over $2 billion was lost, caused mainly by write-downs resulting from the bank's exposure to sub-prime derivatives.
This is the first loss suffered by the firm for five years - by way of comparison, for the first quarter last year Credit Suisse posted a profit exceeding $2.5 billion.
Announcing the loss, Brady Dougan, chief executive of Credit Suisse, expressed scepticism that the effects of the credit crunch were abating.
"In this crisis, a number of times people have seen a light at the end of the tunnel and it has ended up being a train coming down the tracks," he commented.
The bank also admitted that "internal misconduct" involving some of its traders was to blame for some of the losses.
So far in 2008, shares in Credit Suisse have dropped by 22 per cent - although this reduction is dwarfed by that of fellow Swiss bank UBS, which has seen share value reduce by 33 per cent over the period.