  The complete one-loop QED initial state, final state and initial--final state
interference corrections to the process e+e- -> pi+pi- are presented. Analytic
formulae are given for the virtual and for the real photon corrections. The
total cross section, the pion angular distribution and the pi+pi- invariant
mass distribution are investigated in the regime of experimentally realistic
kinematical cuts. It is shown that in addition to the full one-loop corrections
also two-loop initial state corrections and even the resummation of higher
order soft photon logarithms can be necessary if at least per cent accuracy is
required. For the data analysis we focus on an inclusive treatment of all
photons. The theoretical error concerning our treatment of radiative
corrections is then estimated to be less than 2 per mille for both the
measurement of the total cross section and the pi+pi- invariant mass
distribution. In addition we discuss the model uncertainty due to the pion
substructure. Altogether the precision of the theoretical prediction matches
the requirements of low energy e+e- experiments like the ones going on at DAFNE
or VEPP-2M.
