They are everywhere: around the water cooler, at the company picnic, and in the board meetings. Backstabbing colleagues can be plain annoying and offensive. This doesn't even begin to mention all the turmoil that their behavior can cause. Dealing with backstabbing colleagues can prove difficult at times, especially when you must work closely with the individual. Confronting the individual may not always be a good idea. There are a few strategies you should try first.
Keep it professional. One of the ways to help cease a coworker’s bad behavior is to consciously choose not to partake in it. By keeping the relationship strictly professional, you can stave off most personal attacks. This may not stop the employee from spreading gossip about you, but if you can keep your cool, it ultimately makes that person look bad. If his antics are work-related, try taking on more solo projects or teaming up with another coworker when possible. In the event that you are required to work with him, be cautious of what you say and do. Do not fall into his trap.
Don't participate in office gossip. When the backstabbing colleague approaches you regarding other employees, immediately let him know that it is inappropriate to bring these concerns to you. As hard as it may be, this should be done in a respectful and polite manner. Explaining that you feel discussing such things can be detrimental to employee morale and you don't want to participate should be sufficient. Then, change the subject.
Know when to take issues to your boss. You don't want to be the employee who's constantly complaining about a coworker. Going to the supervisor should be a last resort unless the backstabbing colleague is affecting productivity or the behavior is along the lines of harassment. If this is the case, you probably aren't the only person in the office who has a problem with his behavior. While you shouldn't run to the boss every time there is a problem, if the harassment is not reported then not much can be done.
Know the difference between backstabbing and constructive criticism. Another thing worth mentioning is whether or not a 'problematic' colleague has actually stabbed you in the back. Could your coworker just be expressing concern about your behavior or performance? Have you given him a reason to pick apart your behavior or to challenge your ideas? Before taking any action to deal with a backstabbing colleague, you should be able to answer no to these questions. If you can't, maybe you should discuss with your supervisor how you could improve. Just remember: no matter what method you choose to deal with this person, you should always be professional.