It depends on two things. 1)If the pubic hair has to be a spesific length for the wax to work. 2)How long your pubic hair is. If your pubic hair is 1/2 inch long and the product says that the hair should be 1/4 inch, yes, you should trim it. If your pubic hair is 1/4 inch and the product says it should be 1/4 then, no, leave it. If your pubic hair is 1/4 inch and the product says it should be 1/2 inch, you may want to try a different method.