This study investigated whether high socially anxious individuals interpret other people's ambiguous behavior in a more negative or threatening manner in comparison to low socially anxious individuals, after controlling for the effects of depression. High and low socially anxious participants (N = 31) gave a speech. During the speech, a confederate performed ambiguous behaviors. After the speech, participants were asked to answer questions about their interpretation of the confederate's behaviors using open-ended questions and rating scales. The results showed that the high socially anxious participants interpreted the confederate's ambiguous behavior in a more negative and threatening manner as measured by the rating scales, and in a less neutral manner as measured by the open-ended responses in comparison to the low socially anxious participants. After controlling for the effects of depression, the effects of social anxiety on the threat rating score remained significant. These results suggest that social anxiety is partially related to threatening interpretations of other's ambiguous behaviors.