Liposuction of the breasts is remarkably safe. Infection is very unusual, as it is in liposuction of other areas. Occasionally there may be a hypertrophic scar that needs to be revised to make it less noticeable.

Because subcutaneous mastectomies involve sharp dissection of breast tissues and creation of a pocket ("dead space") where fluid can collect, a hematoma is a possibility. Any increased swelling, pain, and bruising on one side may signal a hematoma. This requires urgent evacuation (removal of the blood that has accumulated and cautery of a vessel if necessary).

Surface irregularities can occur. These may respond to a touchup liposuction or sometimes to fat injection to treat a depression. It is important that the surgeon leave a cushion of breast tissue under the nipple to avoid a saucer-like depression which can be difficult to correct. This is sometimes a problem for patients who have been treated previously by non-plastic surgeons.