The hollow fiber based haemo dialyzer made and extremely important impact in haemo dialysis practice in the last three decades. Many people with renal diseases were able to improve their life expectancy and maintain a somewhat improved health-lifestyle. With the prospect of doubling the number of renal patients in Europe and North America by 2020, and expected improvement of health care in developing nations current dialysis treatment models and practices need new approaches and above all new technical solutions. It appears that the hollow fiber technology has met technical limitations in further development of dialysis practices. The most obvious limitations are: i) high flow rate of dialysate with respect to blood flow rate and associated cost of dialysate, ii) inability to scale down the size of the hollow fiber dialyzer for pediatric use, or everyday nocturnal dialysis in adults without dramatic reduction of dialyzer efficiency, and iii) inability to increase the overall mass transfer rate and thus reduce the cost of both dialyzer and dialysate used. Microchannel haemo dialyzers with flat membranes, developed at Oregon State University, holds many promises that are pertinent to the needs of renal patients and healthcare providers.