Reaming and non-reaming of intramedullary nails in long bone fractures was a controversial and even emotional topic in recent decades. This article gives an historical overview of the development in this field and presents the background to the need for unreamed nailing. Furthermore, the current state of knowledge is illustrated by describing the results of a series of randomised controlled trials. Before the year 2000 nearly all German handbooks on orthopaedic and trauma surgery recommended unreamed intramedullary nailing as a more "biological" treatment that causes less harm to vascularity with equal or even better results. Unreamed nailing was in particular advocated for the treatment of open fractures. The tide turned as randomised controlled trials conducted since 2000 gave evidence that unreamed nailing leads to a higher rate of delayed or non-union, while the advantages to blood supply and infection rate could not be proven. According to evidence based medicine isolated femur and tibia fractures should be nailed in a reamed procedure. In a severe multiple injury setting it is safer to stabilize long bone fractures with external fixators, as adverse events are described for reamed and unreamed nailing.