[en] The absorption spectra of HCN and DCN were measured from 130 to 80 nm. Strong absorption bands were observed below 122 nm both for HCN and DCN. These bands were assigned to the Rydberg series converging to the first and the second ionization potentials and to valence transitions at about 120 and 115 nm. The absorption coefficients for HCN were determined over entire range studied. The maximum absorption coefficient, at 112.39 nm, was measured to be 2.8 x 103 cm-1 with an estimated uncertainty of about 20%. (orig.)