This is the first major study on bell beaker pottery in the Middle and Lower Guadiana basin (south-western Iberian Peninsula). Recent archaeological excavations in the area, because of the construction of the Alqueva dam, have provided new and substantial information relating to the 3rd millennium BC. This work contributes not only to the currently known bell beaker pots, but also to information related to their archaeological contexts. There are 54 known sites with beaker pottery throughout the region under study, which is noteworthy if one takes into account that this area was considered as marginal with regards to the beaker phenomenon twenty years ago, when only a few sites had been identified.