In 1954, he graduated from the Faculty of History of Tbilisi State University (TSU), where he was also a professor from 1967 until his death in 2004.
In 1991, he was elected Academician of the Georgian Academy of Sciences (GAS).
Chilashvili was also Director of the Georgian National Museum of the GAS (1980–2004).
Levan Chilashvili's main fields of scientific inquiry was archaeology and the history of ancient Georgia.
From 1995 to 2003, Chilashvili's archaeological expedition in Nekresi (the Kakheti region of Eastern Georgia) discovered early Georgian inscriptions which he controversially dated from the 1st to the 3rd centuries AD.