Abstract: The invention is directed to a synergistic radiation protective pharmaceutical composition comprising 50 to 350 parts by weight of aminoalkyl-thiol-derivatives of the general formula II ##STR1## wherein R.sup.3 stands for hydrogen, or carboxamidinoR.sup.4 stands for hydrogen or carboxy,B represents hydrogen or carboxamidino with the restriction that at least two of R.sup.3, R.sup.4 and B stand for hydrogen--or a pharmaceutically acceptable acid addition salt thereof, 0.2 to 2 parts by weight of .omega.-acylamino-alkane-derivative of the general formula ##STR2## wherein R.sup.1 stands for hydrogen, C.sub.1-4 alkanoyl, aroyl or aryl-(C.sub.1-4)-alkoxy-carbonyl,R.sup.2 stands for hydrogen, or carboxy optionally esterified by C.sub.1-4 alkoxy or aryl-(C.sub.1-4)alkoxy,A stands for --SO.sub.2 OH or --O--PO(OH).sub.2,n stands for 1, 2 or 3 andm stands for 2, 3 or 4--or a pharmaceutically acceptable salt thereof,and pharmaceutically acceptable carriers, diluents and/or solvents, and/or other formulating excipients.