The formation of massive stars is not simply a scaled-up version of low mass star formation. I shall describe how massive stars can grow due to accretion onto a less massive object through an accretion disk. The accreting star quickly evolves to hydrogen burning and can begin to influence its surroundings, including its accretion disk, as a result of intense UV irradiation and a stellar wind. The newborn massive star can stunt the mass growth of nearby lower mass companions. Relatively long-lived UCHII regions will commonly result.