Panagiotis Gravalos studied Painting at the School of Fine Arts under the great painters and professors Spyros Papaloukas and Yannis Moralis.

The professor of Engraving, Yannis Kefallinos, who noticed his designs and excellent engraving, recommended that he should also work with engraving. However, his collaboration with the great engraver A. Tassos made him choose Printmaking and how to practise it.

A firm believer in the social and educational role of art and the artist, Panagiotis Gravalos taught Engraving at the Athens Technological Institute of the Doxiadis Schools from 1961 to 1967. He was a founding member of the Centre for Visual Arts. From 1966 to 1993, he was a permanent associate of the Hellenic Post and was the designer of many series of stamps, for which he won international awards.

In 1971, a sports poster he had designed won first prize in a worldwide competition in Warsaw. Since then, it has been exhibited at the Museum of Graphic Arts in Poland.

From 1986 to 2000, he was an artistic collaborator of the Ionian Bank.

He designed many of the pins for the Athens Olympic Games. He also designed the 24 official commemorative coins issued by the Mint of the Bank of Greece, eight gold and 16 silver, and was the artistic adviser of the medals for the Olympic and Paralympic Games.