Efficient activation of antigen‐specific T cells requires co‐stimulatory signals provided e.g. by CD28. Re‐exposure to antigen and CD28 co‐stimulation reduces activation‐induced cell death (AICD) and increases the number of T cells performing effector functions. AICD is mediated predominantly by CD95 (APO‐1/Fas) and its cognate ligand (CD95L). In an in vitro model system, using human peripheral activated T cells, we demonstrate here that co‐stimulation prevents CD95L expression. Moreover, we show that co‐stimulation reduces the activity of the CD95 death‐inducing signaling complex and procaspase‐8 activation. In parallel, co‐stimulation strongly increases expression of the short form of the FLICE‐inhibitory protein c‐FLIP_short and of Bcl‐x_L. These data provide important new insight into the molecular mechanisms of apoptosis resistance in co‐stimulated T cells.