Nineteen alpha-amino acids were pyrolysed at 600-degrees-C using an integrated pyrolysis-gas chromatography/mass spectrometry system. Pyrograms, tabulated mass spectra and proposed identifications of the main pyrolysis fragments are reported. Diagnostic pyrolysis fragments were recognised for most of the alpha-amino acids (with the exception of histidine, glycine, serine, alanine and threonine) and their formation is rationalised by proposing four thermal degradation pathways.