N-Acyl-.alpha.-aminocarboxylic acid derivatives of the formula ##STR1## wherein L, R' to R'" and Q have the significance given in the description, can be used for the treatment or prophylaxis of illnesses which are caused by the binding of adhesive proteins to blood platelets and by blood platelet aggregation and cell-cell adhesion.

A compound of the formula ##STR1## wherein R.sup.1 to R, R.sup.a, R.sup.b X, Y, Z, m and n have the significance given in the description, can be used as medicaments, especially for the treatment and prophylaxix of conditions which are associated with endothelin activities.