When should I ask for a salary increase or should I look for a new job?

I am a nurse practitioner who is currently working for a major hospital in clinical research. I have done so much more than what was expected of me when I was first hired (coming in on the weekends to treat patients without being paid extra, staying up to 12 hours a day to treat patients, etc.) I am a terrific clinician and have received wonderful reviews from my collaborating physician. However, I have been working at this location for 18 months and have not received a pay increase. My co-workers have told me that this institution only gives 3% raises once every 3 years?!?!?!? Should I look for a new job or should I ask my boss for an increase? I am not used to asking for a pay increase because I have always just been given one without asking.

Go ahead and ask. But do it nicely and politely; use no threats and don't put yourself in a position where you'll have to leave if the boss says "no."

Repeat to your boss all the good stuff you've told us. Then tell the boss that you like your current job, but are having trouble getting by on your current salary and you would like an increase. The worst that can happen is s/he'll say no.

Don't mention what your co-workers said about every three years. But if you hear that from the boss's mouth, it might be true. If so, you might want to think about moving on. It may be the only way you'll get more money without waiting another 18 months.

I would ask for a pay increase!!!

This is a tough one for a nurse. You have to contend with a corporate culture that thinks every one is paid too much. If you were here in California you would have to put up with the fact that tis nonsense is promoted by the governor.

Since good nurses are in demand, your best chance probably comes from job shopping.

you should have known about the rules about raises when you started. At that time you should have known if and when you would be in line for a raise. If you feel you have gone above and beyond the call of duty, talk to your boss.

The policy according to your co-workers is that the hospital gives 3% increase every 3years.
Asking your boss for an increase is not necessary since you are now aware of the policy. Your extra hours on the job and dedication is noticed already by your collaborating Physician, who definitely will pass it to the Management. However, if you are not satisfied again with your income , look for another job.

The best way to approach your boss for an increase in pay, is to find a better paying job at another Hospital.
Try to get hired for that job. If you get the job, now you have bargaining power with your boss.
Don't tell him what you have been offered. Tell him that you deserve a dollar more an hour, than the new job will pay.
This way, if you don't get what you want you can take the new job, and tell the old ungrateful boss to go pound sand up his- Oh! you get the idea!