Molding helmet therapy is a widely accepted treatment for positional plagiocephaly that is generally considered to be low risk. Multiple large outcome studies have shown good results, but adverse events are rarely reported. The literature on helmet therapy was reviewed to clarify the clinical experience with associated complications. Although significant complications were extremely rare, there was a large degree of variability in detection of lesser problems such as minor skin irritation. Patients with a primarily brachycephalic morphology may be at higher risk for poorly fitting orthoses. Most reported complications are minor and self-limited. Maintenance of good helmet hygiene appears to be the most effective strategy for reducing or eliminating complications.