Hemodialysis is considered a treatment of choice for patients with renal failure worldwide, allowing the replacement of some kidney functions by diffusion and ultrafiltration processes. Over 4 million people require some form of renal replacement therapy, with hemodialysis being the most common. During the procedure, contaminants in the water and the resulting dialysate may pass into the patient's blood and lead to toxicity. Thus, the quality of the associated dialysis solutions is a critical issue. Accordingly, the discussion of the importance of a dialysis water delivery system controlled by current standards and recommendations, with efficient monitoring methods, disinfection systems, and chemical and microbiological analysis, is crucial for improving the health outcomes of these patients. The importance of treatment, monitoring, and regulation is emphasized by presenting several case studies concerning the contamination of hemodialysis water and the adverse effects on the respective patients.