Stuttering is a complex speech fluency disorder with complex etiology and manifestations. This paper concerns the familial and genetic bases of stuttering, as well as the characteristics of the sample of persons who stutter and have a positive family history of stuttering. Familial aggregation studies estimate the risk of a disorder emerging in relatives of affected probands when it is believed the disorder isn't caused by environmental, but genetic factors. This paper aimed to analyze the familial aggregation of stuttering in based on a sample of 14 family trees of adults who stutter and have a positive family history of stuttering. The study was conducted via an online questionnaire on the platform Google Forms. The analysis of familial aggregation was conducted by calculating stuttering frequency among different relative categories. The significance of the obtained results was verified with Chi-squared tests for male and female relatives of participants. Specific information regarding the sample was processed with descriptive statistics and qualitative analysis of answers. Results have shown no statistical significance in the frequency of stuttering among male and female relatives of participants of both sexes. The limitations of this study, such as the size and composition of the sample, as well as the materials and research methods implicate that the results need to be taken with caution. However, this paper has provided valuable information about the specifics of a sample of people who stutter with a positive family history of stuttering.