The Maillard reaction plays an important role in the formation of the aroma and flavour of many foods, especially heat-treated foods. Among the volatiles formed, alkylpyrazines contribute to the sensory characteristics of a great number of foods. This article presents results obtained in an investigation of the odour properties of purified, synthetic alkylpyrazines. Dynamic air-dilution olfactometers were used to present the stimuli to 10 panellists. Odour detection thresholds were estimated for 13 alkylpyrazines. Panel results for the compounds investigated were in the range from 4 to 490 p.p.b. (v/v). Alkylpyrazines containing ethyl substituents had, in general, threshold values in the lower part of this range. Odour intensity functions (I = k x C(n)) of five alkylpyrazines were estimated by an odour intensity matching technique. n-Butanol was used as the odour inensity reference. The exponent n of the odour intensity functions ranged from 0.44 to 0.58.