Introduction. Sexual dysfunction is a significant complication of diabetes mellitus (DM). Men with DM may develop erectile dysfunction and a lack of sexual desire due to the nature of the disease and its complications. This study aimed to assess the effect of sexual dysfunction on the quality of life (QoL) in men with type 2 DM. Methods. This study utilized a single-center, descriptive design and was carried out between November 15, 2021, and August 24, 2022. It included 378 male patients with type 2 DM treated at the internal medicine outpatient clinic at a university hospital in Turkey. The data were collected using the Personal Information Form developed by the researchers, the Arizona Sexual Experiences Scale (ASEX), and the Diabetes-Specific Quality of Life Scale (DSQOL). Descriptive statistics, Kruskal-Wallis test, Mann-Whitney U test, Spearman correlation coefficient, and multiple regression analysis were used to assess the data. Results. Among male patients with type 2 DM participating in the study, the mean ASEX score was 14.47 ± 3.37 and the DSQOL score was 2.92 ± 0.31. The relationship between the mean ASEX and DSQOL scores and various factors such as age, education status, employment status, regular health check-ups, duration of diagnosis, type of treatment, fasting blood glucose level, HbA1c level, and body mass index was found to be statistically significant (p < 0.05). A negative correlation was identified between the mean ASEX and DSQOL scores (p < 0.001). Additionally, multiple regression analysis revealed that QoL, duration of diagnosis, marital status, and education status were significant factors influencing the sexual dysfunction levels of the participants (p < 0.001). Conclusions. This study found that as individuals’ levels of sexual dysfunction increased, their QoL decreased. Therefore, it is recommended to assess sexual dysfunction thoroughly and implement training programs aimed at improving sexual health to enhance individuals’ QoL.