Let M be a left module over a ring R and I an ideal of R. M is called (a) an (weakly) I-supplemented module if for every submodule X of M, there is a submodule Y of M such that X + Y = M, (X \ Y IM) X \ Y IY and X \ Y is PSD in (M) Y . We study some properties of weakly I-supplemented modules. We also characterize I-semilocal modules using weakly I-supplemeneted modules.