Natural matrices represent a rich source of biologically active compounds and are an example of molecular diversity, with recognized potential in drug discovery. In the present work, the infusions of Matricaria recutita L. (German chamomile) and Chamaemelum nobile L. (Roman chamomile) were submitted to an analysis of phenolic compounds and evaluation of bioactivity. Phenolic compounds were characterized by reversed-phase high performance liquid chromatography coupled to diode array detection and mass spectrometry with electron spray ionization (HPLCDAD/ ESI-MS). The bioactivity of the samples was tested in different human tumour cell lines (breast- MCF-7, lung- NCI-H460, colon- HCT -15, cervical- He l a and hepatocellular- HepG2 carcinomas}, and the hepatotoxicity was evaluated using a porcine liver primary cell culture (nontumour cells, PLP2) [1 ,2]. The major compounds found were luteolin 0-acylhexoside in German chamomile, and 5-0-caffeoylquinic acid and an apigenin derivative in Roman chamomile. The highest potential antioxidant activity was showed by German chamomile in all the in vitro assays. Both the infusions showed inhibitory activity of the growth of HCT -15 and He la cell lines, without hepatotoxicity (GI 50>400 μg/ml). Nevertheless, Roman chamomile infusion presented the highest inhibitory activity for all the cell lines (GI50<168 μg/ml ). Overall, infusions of both chamomiles contain important phytochemicals with bioactive properties to be explored in medicinal, food, and cosmetic industries.