Objective: The aim of this study was to evaluate voice-related outcomes of long-term androgen treatment in trans male individuals. Methods: Trans male individuals who were under hormone treatment for at least one year were evaluated. Self-Perception of Voice Masculinity (SPVM) scale, adapted Transsexual Voice Questionnaire for trans males (a-TVQ FtM), Voice-related Quality of Life (V-RQOL), and the mean fundamental frequency (f0) were used to assess voice outcomes. Results: Of the thirteen trans male individuals in this study, the mean age was 26.15 years. The median SPVM was 4, which equated to "somewhat male". The median f0 was 119 Hz and did not differ from Turkish cisgender male normative data. The median a-TVQ FtM scores showed a decreasing trend and the median V-RQOL scale scores showed an increasing trend in accordance with the decrease of median f0 scores. Two individuals were within a gender ambiguous f0 range and a failure rate of 15.4% was observed. Of these two individuals who were still within a gender ambiguous f0 range, one perceived his voice as gender neutral, while the other one perceived his voice as very male. Conclusion: Cross-sex hormone treatment was largely effective in voice masculinization for trans male individuals seeking treatment. Its pitch lowering effect is associated with a significant improvement in the voice-related quality of life of trans individuals, especially in vocal identity. In some cases, a cisgender male frequency may not be achieved. This situation should be evaluated with caution when discussing treatment outcomes and the necessity of additional interventions.