Sure you can cut your hair prior to a hair transplant. I would check with your hair transplant surgeon, obviously, but know that if you’re having a linear strip procedure, the longer your hair is in the donor areas the less likely it is for the linear sutured wound to be seen following the transplant, as hair is used to cover the sutures. If you are having an FUE procedure, I would have the physician who is performing the FUE procedure trim your hair, as there’s a fairly specific length (eg: 1-2mm) needed for FUE procedures.I remember this one patient who came to me for an FUE procedure in 2004. During his consultation he had his hair at about 2 inches long all around. I told him during his consultation that we’d be trimming his hair down very short for the FUE procedure, as it was manual back then, and I needed to estimate the angle of the hairs under the skin of the scalp using the hair protruding from the scalp. However, on the morning of surgery, he decided to shave his head with a bic razor...right down to the scalp, and since there was no hair outside the head to observe and make an estimation on the angles inside, I was forced to cancel the surgery altogether, as it was impossible with the hair shaved right down to the scalp.Bottom line: check with your hair restoration surgeon