Adalimumab (ADA) is a monoclonal antibody. Published studies indicate that its use in patients with rheumatoid arthritis can be efficient in providing long-term benefits. The aim of this study is to evaluate the efficacy and safety of ADA for treating rheumatoid arthritis. A systematic review was performed to search for randomized clinical trials that compare subcutaneous doses of ADA 20 mg weekly or 40 mg every other week with placebo, with or without concomitant methotrexate. Only studies of moderate or high quality were included. A meta-analysis was conducted to assess the efficacy (based in changes of American College of Rheumatology ACR criteria) and the safety (based in serious adverse events, serious infections, malignancy and deaths) of ADA use. Withdrawals due to adverse events or lack of efficacy were also evaluated. Eight studies met the inclusion criteria, comprising 2,692 patients. In the efficacy meta-analysis, a greater number of ADA-treated patients relative to those in placebo group achieved ACR20, ACR50 and ACR70 values from 6 months to 2 years of treatment. For safety results, there were no statistically significant differences between the groups. Withdrawals due to adverse events were higher in ADA group relative to the placebo group, and withdrawals due to the lack of efficacy were higher in placebo group relative to the ADA-treated group. This meta-analysis shows a higher efficacy of ADA relative to placebo, but clinicians should be careful regarding adverse events in ADA-treated patients.