The Agrinio Archaeological Museum was founded in the 1960s and was housed in a building that was built with the donation of the Papastratos Brothers, who were involved in smoke trade in the early 20th century. The Papastratou brothers took care of their birthday city and offered it with a multitude of works, including the Archaeological Museum of the city. The Museum was inaugurated in 1969 and operates in the same building until today. The large number of archaeological sites in the prefecture always supplied the Museum with new findings.

The Archaeological Museum of Agrinio is located in the south-eastern corner of the Papastratiou Park, next to the old Papastrateio Library. Half of the building housed the Municipal Library and the other half the Museum. Now the entire building houses the Museum and the two built-in halls of the Library serve as a workshop and warehouse.

Museum collections are exhibited in the small anteroom in both rooms, including vases, tools, metal objects, tombstones and sculptures from various locations in the prefecture. The museum contains the cultural treasures of the wider region of the prefecture that date back to the Neolithic period (7,000 BC) until the end of Roman rule (4th century AD)