Teriflunomide 14mg is a once-daily oral disease-modifying treatment for relapsing-remitting multiple sclerosis. We examined adverse event (AE) profile and efficacy in real life. In this observational cohort study, we retrospectively examined 1521 blood samples and data of 102 patients followed for up to 28months. The number of female patients starting teriflunomide peaked in the fifth decade, 10years later compared to male patients (P<.001), reflecting pregnancy concerns. Seventy-six percentages of patients shifted to teriflunomide from treatment with interferon-beta. Expanded disability status scale improved in 11% of patients (18.2±3.6months follow-up) and remained constant in 67.5% (15±5.3months follow-up). Of ten relapses, three occurred within 6months after starting treatment. Seventeen patients (16.5%) discontinued teriflunomide: 53% because of AEs and 29% because of relapse. Levels of alanine aminotransferase (ALT) remained normal in 95.3% of the blood samples and remained below 1.5 times the upper limit of normal in 91% of the 4.7% abnormal samples. One-third of the patients had abnormal ALT values at least once. Haematological abnormalities were found in <4% of the blood samples, but at least one abnormal value was observed in up to 21% of the patients. Efficacy and safety of teriflunomide in real-life setting support data obtained by the pivotal trials. Laboratory abnormalities are rare among the large number of samples, but patients may commonly have a single mild, abnormal value if frequently tested.