Pyrrolizidine alkaloids (PAs) are widely distributed in many plants including medicinal herbs. The hepatotoxicity of PAs has been known academically for a long time, however, their reproductive toxicity, mutagenesis and carcinogenicity have been less researched. This article is an overview of the clinical and experimental reports of the reproductive toxicity, mutagenesis and carcinogenicity of PAs, the effective factors and generating mechanism of the toxicity.