Pyrrolizidine alkaloids (PA) are toxic for human and livestock. They undergo a metabolic toxication process in the liver which is the first target organ for PA poisoning. Worldwide many episodes of human PA intoxications are well reported. In many cases the reason for these intoxications has been PA contamination in food. The main tools for analysing food and fodder on PA content are based on GC and HPLC separation, followed by MS(-MS) detection. Actual incidents with toxic PA are the 'Jacobaea vulgaris (syn. Senecio jacobaea) problem' in Europe and the 'Ageratum conyzoides problem' in Ethiopia.