Not getting along with a co-worker is more than just an workplace annoyance; it can affect your ability to do your job, and if the problem persists long enough the resulting stress might even affect your health. If you've already tried to work things out on your own and haven't gotten anywhere, it might be time to bring the matter to your boss's attention. Doing so properly can mean the difference between being deemed a problem-solver and looking like someone who can't handle conflict.
It's a supervisor's job to deal with problems that arise in the workplace. If you approach your boss with something like, "Cathy really gets under my skin. I really dislike working with her," you aren't giving him anything to work with. Before you speak to him, document the behavior that bothers you. For example, if you've found your colleague sitting at your desk uninvited for three mornings in a row, say so. If she's caused two of your appointments to cancel because she was rude on the phone, let him know when that happened and what you have already done about it. Then he can make the next move.
Harness your emotions before you set foot in your boss's office. This might be difficult if the coworker with whom you don't get along has just started a 1,000 page job on the copy machine minutes before you needed it for an important presentation, but you won't be taken seriously if your boss thinks your emotions rule you. Take a few deep breaths and calmly let your boss know about the situation.
Focus on Business
Frame the problem as a business issue rather than a personal complaint, advises human resources expert Dr. Marie McIntyre. Otherwise, you risk your boss thinking that the problem is personal in nature and that you are whining. If the issue with your colleague is indeed personal, McIntyre advises letting it go, as everyone must work with people who have aggravating behaviors and personalities. For example, if your coworker makes ugly remarks to you, tell your boss you are worried about customer perception of the business as his animosity spills over into the public work environment.
Let your boss know what actions you are willing to take to remedy the situation. If your co-worker tends to gossip about you, for example, assure your boss that you will refrain from confronting her or retaliating, but would like his advice on how to handle the situation. Avoid issuing your boss an ultimatum such as "If she doesn't go, then I will," advises psychologist Sherrie Bourg Carter in a July 2011 article in "Psychology Today." You take the risk that the boss will, for reasons unbeknownst to you, allow you to turn in your resignation.