Juvenile idiopathic arthritis (JIA) is a chronic inflammatory disorder that may cause joint destruction. Biological treatments targeting specific cytokines and cell interactions have transformed the outcomes of JIA. This review focuses on the selection of patients for and the timing and selection of biological treatment in JIA. Tumor necrosis factor (TNF) inhibitors remain the first choice for polyarticular JIA, followed by abatacept and tocilizumab. Monoclonal-antibody TNF inhibitors and abatacept are usually chosen for methotrexate-resistant uveitis. Recent clinical trials of canakinumab, rilonacept, and tocilizumab have obtained great improvement in both systemic and arthritic features in chronic systemic JIA patients. Current guidelines support the early use of a short-acting IL-1 antagonist for macrophage activation syndrome, a life-threatening complication. TREAT and ACUTE studies suggest that a therapeutic window of opportunity during early disease may exist in JIA. Early initiation of biological therapy may be associated with slower progression of joint damage and longer remission.