[1] The name «Pachalum» originated from the Pachecas' game which men practiced under the shadow of a "Chalum" tree during the early years of the 20th century.

Pachalúm was mentioned for the first time in 1817, as place for sugar production settled by Spanish families that arrived there from San Martín Jilotepeque, Santa Cruz El Chol and from most of the modern Baja Verapaz Department.

[2][3] Pachalúm is located in Sierra de Chuacús, specifically at the bottom of Tuncaj Hill, where several sprinkles come down.

It is also close to the Motagua river basin, cuyos afluentes, los ríos Las Vegas y Tumbadero, humedecen el terreno de la localidad.

[3] The first elections ever held in Pachalúm resulted in victory of Vicente de la Roca in 1986, but his term was not that effective due to the lack of experience on managing a municipality; the next mayor was Rafael Elías who focused on the area development.