Eyadéma was a central player in the demise of Togo's post-colonial democratic government. In 1963, the demobilized colonial soldiers demanded integration into the Togolese army. When President Olympio refused, his government was overthrown in a military coup. Eyadéma was instrumental in planning that coup and is rumored to have personally executed Togo's first head of state. He was immediately promoted and, within two years, attained the rank of lieutenant colonel and chief-of-staff of the armed forces.
As chief-of-staff, Eyadéma held considerable power over the civilian government he and his colleagues installed. By 1967, Eyadéma had grown dissatisfied with the authoritarian leadership of Nicolas Grunitzky and overthrew him in a bloodless coup. A new government under Colonel Kleber Dadjo lasted only a few months before Eyadéma seized power again—this time for himself.