Major complications are rare, including nerve injury, bleeding, and infection, which are rarely a problem for more than a few days if they should occur. Rare instances of longer-term pain due to nerve injury can occur, but careful anatomical approaches can often reduce this possibility. Malignant spread is possible; however, such instances must be rare, as the literature would indicate that local recurrences after FNAB are infrequent if they occur at all. Many subsequent operative approaches incorporate excision of the FNAB site, which is a reason for the FNAB to be performed by the operating surgeon who can plan the definitive surgery. Failure to diagnose is a potentially very serious risk using FNAB, but this procedure should be combined with clinical assessment and imaging. It is worth explaining to the patient that FNAB is not always capable of diagnosing with absolute accuracy. False negative and even false positive diagnoses can occur. The level of risk of both failure to diagnose, or spread of malignancy, is determined by many factors, and is given here as an overall guide only. Careful planning, explanation, and follow-up with a cooperative patient approach is often very useful in reducing these risks substantially. Pneumothorax is a risk of FNAB performed close to pleura or across/within lung, diaphragm, mediastinal tissues, or at the root of the neck. If risk of pneumothorax is high, admission to hospital for close observation may be wise. The patient should be informed to actively seek the results to avoid inadequate follow–up, and to return if the lump changes or enlarges, even if the FNA is not diagnostic, depending on the circumstances.