A method for treating benign prostatic hyperplasia (BPH), prostatitis, and/or prostate cancer, including the step of administering an isothiocyanate functional surfactant to a patient affected by benign prostatic hyperplasia, prostatitis, and/or prostate cancer. In a preferred embodiment, the protonated form of the isothiocyanate functional surfactant is represented by the following chemical structure: