Fractures of the humeral shaft are common. Most of them can be successfully treated without surgery. In some cases, an operative intervention may offer faster and better functional results. One of the major problems with the open plating osteosynthesis is the extensive soft tissue stripping and disruption of periosteal circulation, caused by extensive surgical exposure, resulting in a relatively high rate of nonunion. Minimally invasive plate osteosynthesis (MIPO) techniques were developed to achieve a biologic fixation, although minimizing the complications of an open reduction. The incisions are small and remote from the fracture site to avoid direct fracture exposure. Thereby, MIPO technique obtains, theoretically, higher rates of union, lower infection risk, and decreases the need for bone graft. In the last years, MIPO has gained popularity with satisfactory clinical outcomes in the treatment of long bone fractures, especially in lower extremity. MIPO for humeral shaft fractures, however, could be a surgically dangerous procedure because of the risk of radial nerve injury. It was described by anterior and lateral approach. Humeral middle shaft fractures are possible to treat with a MIPO technique through an anterior, lateral, or a posterior approach. However, when the fracture is near the olecranon fossa, anterior approach is not possible as there is not enough space in the distal fragment to insert the amount of screws required to achieve stability. In this case, the posterior approach may be a good option for treatment. This article describes the MIPO technique through a posterior approach for the treatment of humeral shaft fractures.