Abstract: The current study focused on the effects of anxiety on balance index in young female university students. A group of 15 female students with a high anxiety score (higher than 42 in Spielberger’s score) and a group of 15 female students with a low anxiety score (lower than 42 in Spielberger’s score) were recruited in this study. The Anteroposterior (AP), Mediolateral (ML) and the overall dynamic Stability Index (SI) of the subjects were recorded by use of a Biodex stabilometer (Biodex Stabilometer System, USA) and were compared with each other. The results revealed a significant difference between the two groups. The subjects with a high anxiety score showed a stability index higher than those in low anxiety group (p<0.005) which simply means significantly less stability in this group. In conclusion, this study showed a less stability index existed in subjects with higher anxiety scores. It could be inferred from the results that carrying out a state anxiety assessment concurrently with a clinical balance test certainly help clinicians to predict the hidden associated instability disorders of the patients.