The reliability of five lower-extremity goniometric measurements of 20 patients with moderate to severe hypertonicity was assessed by three pediatric physical therapists. The measurements were repeated on five of the children within one week. Intra-rater variation was less than inter-rater variation for all measurements, but variations of 10 to 15 degrees were found in inter-rater measurements. Intra-rater reliability was acceptable for measurements of hip extension, hip abduction and knee extension, but not for straight-leg raising or dorsiflexion.