Abstract A fast and environmentally friendly procedure has been developed for Fourier transform Raman (FT-Raman) determination of a quaternary ammonium compound, Mepiquat chloride, in pesticide emulsifiable concentrate formulations. The method is based on the measurement of peak area values between 711 and 701 cm −1 corrected using a baseline defined at 620 cm −1 and interpolated in an external calibration of Mepiquat chloride standards dissolved in water. FT-Raman spectra were collected over 1.5 min from samples confined in screw cap standard chromatographic glass vials, at a nominal resolution of 4 cm −1 accumulating 25 scans per spectra and using a laser power of 1000 mW. Five commercial samples containing around 4.5% (w/v) Mepiquat chloride (3.8% (w/v) Mepiquat) were analysed by the proposed FT-Raman procedure and results obtained were statistically comparable with those obtained by a chromatographic reference procedure. The developed FT-Raman procedure does not use toxic or harmful solvents and also minimises the contact of the operator with toxic products, being a fast alternative to the chromatographic procedure.