Generally, acupuncture is relatively pain-free, although this can vary from patient to patient. The intensity of any pain usually depends upon the nature of the condition being treated and its severity, along with the location of needle insertion. Any pain is usually very brief.
Your acupuncturist will be using needles which are very fine and flexible. The needles are usually inserted only to a few millimetres. If this is a worry, your acupuncturist can use even finer needles or needle-free techniques.