Background: Fractures of the humeral shaft accounting for approximately 3% of all fractures. There is a wide array of good options for their treatment and controversy over the best methods. Although good techniques of osteosynthesis are available, the aim of this article is toemphasize on the benefit and good outcome of conservative treatment for properly selected cases to decrease the cost and avoid the complications of surgery. Method : During the period from February 2011 to June 2012 fifty-five fractures of humeral shaft were treated at orthopedicdepartment in the ALKindyteaching hospital. 22 fractures considered suitable for the study. The patients treatedconservatively by using the‘U’ shaped coaptation slab. Then we shift to POP cast or functional brace after one week.Then we follow the patient clinically and radiologically every 2weeks until the fracturehad united and the limb functions were restored. The outcome of treatment was assessed by specificparameters which include alignment, rate of union and limb functions. outcome: This study showed thatthe initial deformities of angulations were considerably reduced by the use of U slab and the POP castwhich act as a dynamic rather than a static splint,or functional brace through soft-tissue compression correcting angulation to less than 30° in coronalplane and less than 20° in sagital plane. Manipulation of the fracture was not required and didnot affectneither the rate of union nor the final position, as the cast appeared to be capable of correctingangulation deformities. Perfect anatomical reduction was found not to be essential for satisfactory limbfunction, which was present with varus angulation and posterior bowing. The incidence of delayedunion compares favorably with other reported series, although the definition of delayed union isvariable. Conclusion: In fracture shaft of humerus, neither rigid immobilization nor perfect alignment are of great importance for final outcome, so conservative treatment is one of the most effectivemethods of treatment and the operative treatment can lead to adverse effect on the outcome in case ofbad judgment and should be limited as much as possible to specific indications