Short answer. It depends.
Long answer: It depends on your reasons for getting rid of your credit cards. If you are looking to remove credit cards in order to remove temptation from your life, get them outta here! Get rid of them right now (don't forget to cancel them).
If you are looking to convert to debit and cash only purchases then you can definitely get rid of your credit cards, although don't cancel them just yet. A variable that they use to calculate your FICO score is called credit utilization. We've defined it a little further here.
When you cancel your credit card you raise your utilization ratio, and in turn lowering your credit score. The best option is to cut up your credit cards, pay off all of the balances, and then keep the accounts around. That way your credit utilization always remain low and your credit score will steadily increase. THERE IS ONE CAVEAT: if your credit card has an annual fee. Aim to pay off the balance as soon as possible.