In the paper a class of fast adaptive Fourier-based transforms were used for spectroscopic data compression. These transforms are based on adaptive modification of the Cooley-Tukey's signal flow graph. The adaptive versions of the cosine, cosine-Haar and cosine-Walsh transform of various degrees were taken as a base for the experiments. The transform kernels are modified according to reference vectors representing a given class of processed data. The results obtained using these transforms for gamma-gamma ray coincidence spectra compression are presented and compared with the results obtained by use of classical transforms. Both classical and adaptive transforms can be used for off-line as well as for on-line compression. (C) 2004 Elsevier B.V. All rights reserved.