Water for dialysis represents an additive risk factors to the chronic inflammatory state documented in patients on ESRD. The possibility of sustaining proinflammatory cytokines through microbial derived products, coming from dialysate or infused solutions, is enhanced by biofilm presence on piping and on water treatment system or monitor components. Spread use of reverse osmosis, loop distribution system and pre-treatment components tailored to local raw water characteristics have greatly contributed to a general improvement in final water quality. Notwithstanding these contributions literature still reports fatal accidents or significant percentage of dialysis units not complying to the water quality standards. Technological improvement lowers chemical contamination but microbial quality relays more on quality assurance programs than on technology. Optimal water quality represents part of the anti-inflammatory strategies we need to assure to our dialysis patients to improve outcome.