- Your company is experiencing a downward spiral
- Your relationship with your manager is damaged beyond repair.
- Your life situation has changed.
- Your values are at odds with the corporate culture.
- You've stopped having fun and enjoying your job
- Your company is ethically challenged.
- you have behaved in ways that are considered improper
- You've burned your bridges with your coworkers.
- Your stress level is so high at work that it is affecting your physical or mental health
- You are unchallenged
Via humanresources.about.com