If you have a letter prefix, you can reliably date the guitar to within 2-3 years. Example: Serial #E21000 is likely a 1976 Eko Cobra.
An is not a precise science like decoding a Fender. It is more like historical detective work. If you own a 1960s Eko, you will likely never know the exact day it left the Recanati factory. But with the guidelines above—focusing on the 5/6-digit range, letter prefixes, and feature-based dating—you can narrow the year down with high confidence. Eko Guitar Serial Number Lookup
No serial number? Do not worry. Italian manufacturing was inconsistent. Here is your fallback plan: If you have a letter prefix, you can