Millstones and grindstones of the prehistoric to Roman periods include saddle querns, rectangular hopper-rubber mills, rotary querns and Pompeian-style donkey mills. Many of these were manufactured from igneous rocks which can be provenanced to their geological sources using chemical analysis, giving information about trade contacts of sites. Sixty-nine samples of 10-20 g each were removed from broken parts of lava millstones of prehistoric and early historic date, from sites in Israel, Syria, Egypt, Greece and Turkey. These were analysed for major and trace elements using X-ray fluorescence, and petrological features were examined in thin section. The millstones were all young generally fresh lavas ranging from vesicular basalt to porphyritic andesite. Potential sources occur in younger volcanics of mainland Greece, the Aegean, Turkey and the Levant (Israel, Syria and Jordan), and in Egypt. Thirty-four geological samples from Israel, Syria and Turkey were collected and analysed in the same way as the archaeological samples, and an intensive literature survey carried out to supplement these by published analyses. Comparison of archaeological samples with source data is done by using a series of discrimination graphs, following a simple flow diagram. The archaeological samples were of two types, within-plate lavas, and island arc or other subduction-related lavas. All samples were successfully assigned to sources, and results show use of the source areas as follows.During the prehistoric period (Neolithic, Bronze Age, pre-6th century BC Iron Age samples) saddle querns in mainland Greece were made of Aegina andesire, while sites in north Syria used local Syrian lavas, and in Israel basalts from near Lake Tiberias and from the Dead Sea area were used. Earlier work by the authors and others has shown import of Levant millstones to Cyprus in the Late Bronze Age. Hopper-rubbers of the 5th century BC onwards were made at specialized quarries in Aegean islands, on Nisyros, Kimolos and Santorini, and exported to mainland Greece, western Turkey, Egypt and Cyprus. Less well-finished hopper-rubbers were made and used in western Turkey and in Israel. Roman Pompeian-style mills were made of Levant lavas from several sources, particularly around Lake Tiberias, and were transported within Israel as well as to Cyprus as shown by earlier studies. Rotary querns were made of lavas from Santorini and probably Nisyros, and of locally-used west Anatolian rocks. Rotary querns of Roman and later (10th-12th century AD) dates were also produced at several sources in the Levant, again around Lake Tiberias and probably in north Syria and within the Dead Sea volcanics, for use within Israel. Olive-crushing trapeta used in Turkey and Greece were manufactured from andesites from Anatolia and Aegina respectively. West Anatolian lavas (mill types unknown) have also been identified at Roman sites in the eastern desert of Egypt.Millstone distributions increased in complexity and extent over time, with hopper-rubbers being traded up to 820 km from sources, and Roman rotary millstones up to 1300 km. The three major source areas—Aegean, Anatolia and the Levant—were in apparent competition by the Roman period, when there is extensive overlap of distributions from different sources, with Aegean and Anatolian products traded the furthest. The millstone trade in the eastern Mediterranean is separate from that of the west Mediterranean (west of Greece) except for one hopper-rubber of Nisyros lava identified in a shipwreck off Mallorca. This dichotomy is in marked contrast to the distribution of amphorae, within which west Mediterranean (Italian) products were widely used in the east from at least the 2nd century BC. Stylistically, east Mediterranean millstones also show differences from those in the west, in the prevalence of hopper-rubbers, and later in decorative Features common on Pompeian-style mills.