Kammala jumla mai zuwa: A ranar 9 ga Mayu, 1967, an zabe shi a matsayin Bishop na Verapaz, yana karbar mukamin a ranar 11 ga Agusta mai zuwa. A wannan matsayin, ya jaddada aikin fastoci tsakanin al'ummomin 'yan asalin mutanen Maya. A lokacin da kasar ke gudana
yakin basasa a cikin shekarun 1970, Gerardi ya kasance mai karfi mai ba da shawara ga amincewa da harsunan 'yan asalin Guatemala, don inganta matsayin' yan asalin. Ya taimaka sosai wajen samun izini ga gidajen rediyo biyu don watsa shirye-shirye a cikin yaren Maya.