Despite massive deportations of Greek Jews to concentration camps, Jews were active in all the various Greek partisan groups Many college and university students from Athens joined the National Liberation Front and carried out attacks on German-held munitions ships moored at Greek ports. As many as 600 Jews were members of Greek People's Liberation Army (ELAS), and Greek Jewish partisans often acted as medical officers in their partisan units.
Greek Jewish partisans also mobilized resistance in their towns and villages, forming ties with other Greek partisans. Jewish partisans in Greece were generally welcomed into Greek partisan units without prejudice.
In 1943 and 1944, as many as 1,000 Greek Jews fought as partisans. Jacques Costis, an Athenian Jew, was a member of a maritime sabotage force that blew up German ships supplying Rommel's Afrika Korps. In the mountains near Larissa, Greek Jewish partisan commander Marcos Carasso destroyed an entire SS battalion that had arrested twelve Jewish families and burned their homes.