Lerna in the Argolid, excavated by J. L. Caskey of the American School of Classical Studies during the 1950's is our best source of evidence for internal chronology, artistic diversity, and cultural organization in the Early Helladic period (roughly the third millenium B.C.). As part of a study of Early Helladic (EH) trade in southern Greece, a selection of pottery and other clay products from Lerna was sampled for provenance determination by neutron activation analysis. Sauceboats and bowls from early and late phases of EH II, as well as tiles and mud bricks from the House of the Tiles (final EH II), served as the compositional reference groups, against which were compared the compositions of characteristic vases from an early EH III phase, sealings form the House of the Tiles, and other objects of particular interest. After presentation of descriptive and analytical data for 40 samples, the compositional uniformity of the majority of the pottery studied is contrasted with the variablility of the results for cruder material and for pieces suspected of being imports on archaeological grounds. -- AATA