Individuals with the fragile X premutation (FXP) are more likely to display elevated levels of autistic traits; however, these traits are not fully understood, and an underlying cause has not yet been studied. A reduction in spontaneous mentalizing has been found among other populations with high autistic traits, and it is widely accepted that this cognitive difference results in the social difficulties that these individuals experience. To explore this hypothesis in women with the FXP, we examined implicit mentalizing performance using an eye-tracking paradigm and evaluated its relationship with self-reported autistic traits. We included three groups: mothers of autistic children (M-ASD; N=27), mothers of children with FXS, who themselves have the FXP (M-FXP, N=20), and mothers of neurotypically developing children (M-NT, N=24). Group membership had a main effect on implicit mentalizing ability, with the M-FXP group showing poorer performance than the M-NT group. These findings suggest that a reduction in implicit mentalizing may be a feature of at least a subset of women with the FXP, but additional studies are required to further examine the mechanistic relationship between implicit mentalizing ability and autistic traits in this population.