Individual polystyrene (PS) and polyacrylonitrile (PAN) solutions in N,N-dimethylformamide (DMF) were studied by electronic absorption spectroscopy. Upon increasing the polymer concentration in the PS-DMF binary system a bathochromic shift of the band at about 260 nm was found. This spectral effect could be explained by an association of PS phenyl groups and/or by a complex formation between DMF and PS. The UV spectrum of PAN in DMF solution was interpreted in terms of the variety of possible donor-acceptor complex formations. The specific intermolecular interactions in the investigated binary liquid systems were discussed on the basis of the spectral data.