Inhibition of angiotensin-converting enzyme (ACE) and antithrombotic properties of peptides released from bovine caseins during fermentation by Lactobacillus casei Shirota and Streptococcus thermophilus were determined. Both species released ACE inhibitory peptides, whereas only Lb. casei Shirota produced antithrombotic activity. The highest thrombin inhibitory activity, 80.7%, was observed at 27 h of fermentation by Lb. casei Shirota. Active peptides were purified by HPLC; seven peptides were obtained, and their resistance to digestive enzymes, pepsin and trypsin, was evaluated. The most active peptide even after the hydrolysis was identified as YQEPVLGPVRGPFPIIV (fragment 193–209 of β-casein): it had an inhibition efficiency ratio for ACE of 0.14%/peptide concentration (μg mL −1 ), and a thrombin inhibition efficiency ratio of 4.6%/peptide concentration (μg mL −1 ). This peptide had been previously reported as an ACE-inhibitor, but this is the first time that it is evaluated for its thrombin inhibition activity.