We report preliminary results of our provenance study of marble from the Telephos Frieze of the Pergamon altar. The emphasis here is on the stable isotope geochemistry of marble. The obtained δ13C values (2.4 to 3.5‰) vary insignificantly. However, the δ18O values give two clusters. The isotopically light marbles (close to −9.5‰) derive from panels 1–8 and the heavy marbles (−3.5 to −1.0‰) derive from panels 11–50. Mineralogical, petrographic and geochemical investigations (accessory minerals, grain size distribution, rare earth elements) further refined the marble characteristics. In spite of certain differences observed (grain size distributions, isotopy and contents of certain elements) for the two marble groups, the present data support a common provenance. So far, east Aegean islands and the Marmara region are favored.