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 1958, Chilashvili received his PhD in History, and in 1967, he received a degree as Doctor of Historical Sciences.
In 1991, he was elected Academician of the Georgian Academy of Sciences (GAS).
Chilashvili was also Director of the State Museum of Georgia of the GAS (1980–2004).
In 1982, he was awarded the Simon Janashia Prize of the GAS.
Levan Chilashvili's main fields of scientific inquiry were archaeology and the history of ancient Georgia. From 1995 to 2003, Chilashvili's archaeological expedition in Nekresi (the Kakheti region of Eastern Georgia) discovered pre-Christian Georgian inscriptions from the 1st to the 3rd centuries.