15 randomized controlled trials comparing electrical stimulation to sham treatment in adults with a fresh fracture, nonunion, delayed union, osteotomy, or symptomatic spinal instability requiring fusion were included. The purpose of this meta-analysis was to quantitatively assess the efficacy of bone stimulation in terms of pain relief, functional improvements, and radiographic nonunion. The results indicated that pain was significantly improved and the risk of radiographic nonunion was significantly decreased with electrical stimulation when compared to the sham control group (moderate-quality evidence). No significant differences were noted with regard to functional outcome (low-quality evidence). Subgroup analysis by clinical indication or type of stimulation did not alter the effects of electrical stimulation.