In the United States during the 1940s Flesch and Gunning pioneered the movement to improve the comprehensibility of government documents Since that time the provision of comprehensible information to the general public has become increasingly important Indeed, most computer programs have the facility to assess what percentage of the population will understand certain forms of written information Vast quantities of written patient information have been produced over the decades and more are being produced daily This literature review sets out to provide an insight into the studies which have looked at the value and purpose of such literature Considering the amount of written patient information in existence the amount of research into this interesting subject is small Many concepts have to be considered Is this information of any use to patients? Can they understand and recall it and does it increase compliance? Are patients satisfied with the amount, quality and detail of written information? If health professionals are to inform their patients fully, written information is an area which should be more fully researched for ethical, quality and economic reasons