It depends on the card and your spending habits. If the card charges an annual fee, consider closing the account so you aren’t required to pay each year. If you’re worried about overspending, consider closing the account so that you don’t run up new charges.
But if the card offers a rewards program that matches your spending habits and has a low ongoing APR, you may consider keeping it open. Closing an account could hurt your credit score by changing your credit utilization ratio and reducing your credit age, so be sure to put some thought into the final decision.