From the Homeric poems to the fall of Byzantium, the ancient Greek literature has enlarged the Greek vocabulary, which has become an agglomerate of words. Greek dictionaries do not contain sufficient information to understand the status, the age and the use of these words. Greek words of Indo-European origin have been widely studied since the late eighteenth century, but little is known about words of non-Indo- European or unknown origin. This thesis therefore maps the Greek vocabulary, focussing on the non-Indo-European part of it. It contains some 1800 words, divided between thirteen semantic categories, which were judged as non-IE by a collation of the standard etymological dictionaries. Of these I have recorded the attestations (from Homer to the thirteenth century AD). Then I (1) collected all their spelling variants, (2) mapped their distribution through literature, lexicography, papyri and inscriptions, (3) traced their chronological distribution, (4) recorded their linguistic status, (5) and documented internal and external comparata that may help to identify their origin. Finally, I identified patterns in attestation, distribution and variability and synthesised the results of this survey.