The series of dyes derived from 1-indanylidenemalononitrile were prepared and characterised. The purity of the dyes was checked by TLC and elemental analysis; the structure of substances was confirmed by 1 H and 1 3 C NMR spectra. The relationships among the structure of dyes, their absorption characteristics and the polarity of a solvent were investigated. The full optimised geometry was computed by AM1 method, the theoretical characteristics of electronic transitions were studied by PPP-MO, CNDO/S and INDO/S procedures. Due to possible application of the studied dyes in textile practice, the colouristic characteristics were determined as well.