Background: The incidence of prostate cancer has seen a gradual rise in Taiwan in recent years. Prostate-cancer patients typically suffer from symptoms of erectile dysfunction and a lower quality of life. Thus, understanding this issue is critical to providing appropriate nursing care to this population. Purpose: This study explored the relationships among patient demographic data, disease characteristics, and quality of life. Erectile function was used as the independent variable. Methods: Convenience sampling collected data from 200 patients with prostate cancer undergoing treatment at a regional hospital in southern Taiwan. The research instruments used included a basic cancer information datasheet, the International Index of Erectile Function, and the EORTC Quality of Life Group prostate specific 25-item module. Data were analyzed using SPSS 19.0 to test our hypothesis. Results: The mean age of participants was 73.2 years and 96.5% had clinical erectile dysfunction symptoms. Erectile function was used as the independent variable. Age, education level, cancer stage, and erectile function correlated with quality of life. Conclusions / Implications for Practice: The results of this study may help health professionals understand the association between erectile function and quality of life in prostate cancer patients. Healthcare professionals may then focus on providing patients with consultation platforms for sexual problems and make appropriate referrals to specialized departments or hospitals to provide better care. Healthcare professionals should focus on the specific needs of prostate cancer patients and provide individualized healthcare to improve the quality of life of this population. [ABSTRACT FROM AUTHOR]