Purpose: The study aim was to determine whether self-reported temperament traits differentiate adults who stutter (AWS) from adults who do not stutter (AWNS). Additionally, associations between temperament and stuttering frequency, and between temperament and quality of life impacts of stuttering, were investigated in AWS. Method: Self-reported temperament traits were documented for 33 AWS and 43 AWNS using the Adult Temperament Questionnaire (ATQ; Evans & Rothbart, 2007). Quality-of-life impacts of stuttering were assessed using the Overall Assessment of the Speaker's Experience with Stuttering (Yaruss & Quesal, 2010). Stuttering frequency was calculated from 100-word monologue and reading samples. Results: A between-groups difference in scores on the ATQ Positive Affect subscale was nominally significant (i.e., before correcting for multiple tests) and also approached statistical significance after Bonferroni correction. Positive Affect scores were lower for AWS, and the size of this trending effect was moderate. Within AWS, a statistically significant positive correlation was found between impact scores on the General Information section of the Overall Assessment of the Speaker's Experience with Stuttering and ATQ Frustration subscale scores after Bonferroni correction. No associations were detected between temperament traits and stuttering frequency. Conclusions: Results reveal a nontrivial tendency for AWS to experience decreased positive affect compared to AWNS. In addition, increased frustration was found to be associated with reduced general knowledge about stuttering in AWS. Neither effect has been previously reported for adults or children who stutter. Finally, self-reported temperament traits were not found to vary with stuttering frequency in adults, consistent with previous results for AWS.