This publication assembles the flint and obsidian tools retrieved from occupation levels dating to the early Neolithic and the Uruk periods that were exposed by the German excavations in Tell Sheikh Hassan. It is the first monograph to present an assemblage of Uruk-time lithics including detailed descriptions of the function of the various tool types. The finds of the early Neolithic are presented in as much detail as there is proof that certain early Neolithic types were, at the time of the Uruk occupation, sought after, collected and put to use again. Another important result is the fact that, for several lithic tools dating to proto-dynastic times, the Egyptian origin could be ascertained -- a first indication of Egyptian imports to the Uruk region.