Once was a brad nailer, twice was a staple gun. I even was knicked pretty bad a different time when a guy who supposedly had experience with building cabinets started working with us and I was holding a tiny board down to a cabinet and made eye contact with him and said, "Please don't shoot my finger" and yeah he did.... but back to your question. I only went to the hospital once but that time I had shot all the way through my finger nail. I'd say as long as you can get the nail out just clean it out really well, then keep applying antibacterial cream on it with band aids covering it up. Its worked for me every time.