The San Pedro Viejo de Pichasca rock-shelter, located some 70 km east of the provincial town of Ovalle in the Limarí Basin is considered one of Chile’s most important prehistoric sites with human occupation evidence dating to at least 9000 BCE. The rock shelter in the foothills of the Southern Andes Mountains is in a semi-arid environment. Since the 1960s there has been much archaeological interest with major excavations occurring between 1960 and 1970 (e.g. Ampuero and Rivera 1971). As part of a detailed survey of the rock shelter walls, many prehistoric painted pictographs), have been discovered and recorded, probably dating to the late Holocene. In July 2013 an Anglo-Chilean/Argentinean team further explored the walls and ceilings of the rock-shelter in order to experiment with different photogrammetric recording techniques, including microscopy and post-site digital analysis. This paper gives a synopsis of the long archaeological history of the site, along with observations and analysis of a number of selected painted panels that are located within the central section of the rock shelter. The various methodologies employed assisted in further understanding the underlying reasons that would have led people to paint in this rock-shelter.