OBJECTIVES: The aim of this study was to evaluate the efficacy, safety and tolerability of 1 and 10 mg/kg belimumab, a biologic drug, for the treatment of Systemic Lupus Erythematosus (SLE) through a meta-analysis, comparing these treatments with placebo. METHODS: A systematic review and meta-analysis of randomized, placebo-controlled trials of belimumab was conducted. Data were collected from several databases until August 2012. Efficacy outcomes included the SELENA-SLEDAI score (Safety of Estrogens in Lupus Erythematosus National Assessment version of the SLE Disease Activity Index), SRI (Systemic Lupus Erythematosus Responder Index), normalization of low C3 (<90 mg/kg), and anti-dsDNA positive to negative. Data on safety included any adverse events, serious adverse events, severe adverse events, death, malignancy, infections, and infusion reactions. We also evaluated withdrawals from treatment due to lack of efficacy or adverse events. RESULTS: Fours studies were included in this study. Anti-dsDNA positive to negative was the most significant efficacy outcome in our meta-analysis for both of the evaluated concentrations. No significant differences in the safety data were observed between the belimumab (1 and 10 mg/kg) and placebo groups. Tolerability results revealed no significant differences in withdrawals due to lack of efficacy and adverse events between the belimumab and placebo groups. CONCLUSIONS: Belimumab exhibited good efficacy results, especially at 10 mg/kg, a good safety profile, and adequate tolerability, which indicates that this biologic drug is a promising therapy for the treatment of SLE. Additional randomized placebo-controlled trials should be conducted to establish the efficacy and safety of belimumab.