In the United States, tamsulosin is the most prescribed drug for benign prostatic hyperplasia (BPH) treatment. However, less is known about the adverse effects and mechanism of action of the drug in the organism. So, the aim of this review is to evaluate the benefits and harms of tamsulosin therapy in patients with BPH. A literature analysis was realized using the database of the National Center for Biotechnology Information (NCBI) MEDLINE®. The data collection was carried out in a retrospective of 10 years from 2008. Thus, we considered some measurements parameters used in different studies for a reliable comparison of the works. Tamsulosin has been characterized as an effective treatment for BPH. However, some studies demonstrate that the epithelial elements remain proliferative even after the administration of the drug and may be involved in the continuous growth of the gland. Also, tamsulosin can directly impact on the ejaculation process, cognitive functions and mental health of men. BPH affects approximately 50% of men between 50 and 60 years old. Beyond that, 90% of men in their eighth decade of life will present anatomical evidence of BPH. Therefore, the treatment with tamsulosin, an α1-adrenergic antagonist that promotes the relaxation of the prostate smooth muscle, is essential to diminish the gland size and restore the urinary flow. However, its administration must be assessed for a better response and lower risk of adverse effects in those patients.