Panzós is a town and municipality in the Alta Verapaz department of Guatemala, historically inhabited by Q'eqchi' and Poqomchi' peoples. The area's land tenure system was shaped by 19th-century liberal reforms under president Justo Rufino Barrios, who granted land to German settlers and Guatemalan military officers, often through the confiscation of Indigenous land. This produced a pattern of land accumulation by a small number of owners and a system of exploitative labor arrangements affecting the native population that persisted into the 20th century.
In 1970, the Guatemalan government under General Carlos Arana Osorio established the Northern Transversal Strip (Franja Transversal del Norte) by Legislative Decree 60-70, designating agricultural development zones across several departments, including Alta Verapaz. This decree formed part of the background to escalating land conflicts in the Polochic river valley.
On 27 May 1978, when local residents of San Vicente, near Panzós, went to work land along the shores of the Polochic river, the sons of a local landlord arrived with armed soldiers and intimidated the peasants to stop them from pursuing land claims. The same day, military personnel detained two peasants in La Soledad and assaulted others; a disturbance occurred in which one peasant was killed. On 28 May, peasants from La Soledad and Cahaboncito presented a document, prepared with the assistance of FASGUA, to mayor Walter Overdick Garcia, asking him to mediate on the peasants' behalf regarding their land grievances.
On 29 May 1978, peasants from several nearby settlements — including Cahaboncito, Semococh, Rubetzul, Canguachá, Sepacay, Moyagua, and La Soledad — traveled to the central square of Panzós to protest land disputes and abuses by landlords and military and civil authorities. Hundreds of men, women, and children gathered, carrying machetes and agricultural tools but no firearms. One participant is quoted as recalling that "the idea was not to fight anybody; we only wanted to clarify the land situation." Following an unclear provocation, the army opened fire on the gathered peasants with machine guns, killing an unspecified number of people; reported death tolls vary between 30 and 106.
As of the 2018 census, Panzós had a population of 22,068. The massacre is referenced in historical accounts of the Guatemalan Civil War and the Franja Transversal del Norte land policies of the period.