In this study the usabilty of a hybrid-P300 BCI communication application was evaluated by four severely motor restricted possible BCI end-users. The P300 BCI was combined with EMG for error correction (see also abstract Riccio et al.). The prototype was evaluated in terms of effectiveness (accuracy), efficieny (time needed to complete task) and end-user's satisfaction. In two copy-spelling tasks accuracy was high (M=92.5% and M=98.75%), but lower in the free-spelling sentence (M=85.02%) and email task (M=75.34%). The hybrid letter correction could be used by all end-users and improved efficiency. Overall, end-users were moderately to highly satisfied with the BCI, but least satisfied with the adjustment (M=3.25 of 5), effectiveness (M=3.25 of 5) and aesthetic design (M=3 of 5) of the BCI, as assessed with the Extended Quest 2.0. One end-user could imagine using the BCI in daily life.