The study investigated the prevalence of fear and hyperacusis and the possible connections between fear, hyperacusis and musicality in a Swedish sample of individuals with Williams syndrome (WS). The study included 38 individuals and a cross-sectional design, with no matched control group. Two persons, who knew the participant well, completed a questionnaire. On reported fears, 58% of the participants scored higher than +2S.D., compared to a psychometric study. Thirteen percent scored above the suggested cut-off for hyperacusis, compared to 2.5% in a psychometric study. Female participants generally had higher reported fears and hyperacusis compared to male participants. There were also startling findings of correlations between reported fears and hyperacusis. This preliminary report supports a hypothesis that fears and anxiety could be associated with hyperacusis in the WS population. A hypothesis that musicality could serve as a protective factor and prevent anxiety, received no or very limited support. A hypothesis that hyperacusis could be connected to a general, readily arousal, tendency in the sympathetic nervous system and could be seen as vulnerability for psychopathology is discussed.