The trade network originating from Chios and Phocaea between the fourth and the seventh century A.D. will be used as a case study to analyze the many differences between data provided respectively by written and archaeological sources in the field of history of trade. Evidence provided by the two disciplines appear to be complementary under many points of view. Therefore, in a methodological perspective both sets of data have to be used, in order to obtain a clearer description of trade in a given period of time.