Iraq is one of the countries suffering from the worst levels of contamination from landmines and explosive remnants of war in the world. The full humanitarian impact of this contamination is largely unknown but it is estimated that there are approximately 300 new casualties per year. Other than landmine, explosions, terrorist attacks, wars, occupation, traffic accidents, diabetes, and others claim the lives and limbs of hundreds of victims each year. In this thesis, a simple, low cost and effective lower limb prosthesis is presented for use in our country and the third world. The purpose of the limb is to enable mobility to amputees and help them in standing, kneeling and maintaining balance. It includes the design of knee joint, adjustable shank, ankle joint and foot. The length of shank can be easily adjusted to suit many types of amputee levels (above knee and below knee) and can withstand a good range of patient heights and weights. The designed and constructed device presented is effective, easily producible and repairable, built in several parts that are compatible with most widely used models and designs found in the market. These parts may be used all together or just selected parts may be attached to the original artificial limb worn by patients. Each part can be easily detached. If one or several parts wear out at different rates one part may be replaced easily and made relatively cheaply from locally found materials like beech wood and aluminum. By using different types of materials, models were designed to fit different kinds of people and different levels of amputation. Adult amputees with some cases of edema in their stumps or amputees that need to change their shoes more often will find the designed models comfortable because they can adjust the height of the artificial limb very easily by them self. Children amputees will get great benefit of adjustable shank design too. Theoretical analyses were made for the designs. And finite element method (by using the ANSYS Workbench program V.12.1) was used to simulate complete stress analysis which indicates that this device would be able to withstand the forces of an average weighted individual involved in actions of walking and kneeling. Also the ISO-10328 Test Standard, which gives the necessary structural testing for lower limb prostheses, was used as the basis for testing.