Two-charged-pion correlations were studied in pp (! 2 + 2 n 0 ; n 0) annihilations at rest with the CPLEAR detector at the Low-Energy Antiproton Ring (LEAR). A strong enhancement w as found in the production of pairs of like-sign pions with a small value of the relative four-momentum Q, with respect to pairs of unlike-sign pions. The observed enhancement w as interpreted as a consequence of the Bose-Einstein symmetrization of the two-pion wave function. The data are well represented by a correlation function parametrized as a double-Gaussian; an exponential parametrization is also statistically acceptable. The value of the correlation strength is found to be > 1. The high-quality large data samples together with the ability for K identication and nal-state separation allowed the study of systematic eects impacting on the Q dependence of the correlation function and on the extracted space parameters of the pion sources.