In sepsis and endocarditis, bacteria and their bacterial toxins plays a major role in the activation of coagulation. In the current study, we analyzed the influence of bacterial toxins such as LPS (E.coli), α-toxin (S. aureus), lysostaphin (S. stapholyticus), exotoxin A and lectin 1 (both of P. aeruginosa) on platelet aggregation. As a quantitative investigation of the aggregation of thrombocytes, the photometric method by Born was used. The results of the experiments demonstrate that bacterial toxins act both, like a physiological activator of thrombocytes (e.g. α-Toxin) as well as like inhibitors (e.g. exotoxin A, lectin 1 and lysostaphin). Likewise, the proaggregatory effect of alpha-toxin can be inhibited dose dependent by medication like abciximab, eptifibatide, Iloprost and interestingly enough also by levosimendan. In the results, Lipopolysaccharide (LPS) on the one hand did not show an inhibitory characteristic nor did it show an inhibiting effect on ADP induced aggregation. For the future, we must think of further experimental medicamentous stategies to possibly obtain new findings for the treatment of sepsis and endocarditis.