These days, it's quite common for employers to run a credit check on potential applicants. Doing so can give them an overall feeling for your integrity, discipline and lifestyle. Also, depending on the position, someone who's heavily in debt might be seen as a risk (cough, cough embezzler). If you have credit troubles, be up front with the employer and explain your circumstances. Unless you've done something really shady (see above parentheses), you should be fine.