The use of an interactive filter for smoothing Raman spectra is described. It is applied by fitting a polynomial to a limited range of data in a spectrum using the least-squares criterion. It provides a variable band-pass with very sharp cutoff without generating ringing artifacts. Its use is demonstrated in tailoring of the filter bandpass to the requirements of individual spectral features, in detection of weak peaks in a noisy spectrum, and in detection of minor component signals when these are superimposed on major component signals.