BACKGROUND To evaluate the efficacy and cost-effectiveness of cell salvage (CS) in reducing allogeneic transfusion in patients undergoing surgery for idiopathic scoliosis. METHODS A case-control study with 42 patients with adolescent idiopathic scoliosis (AIS), submitted to posterior arthrodesis with instrumentation from 8/2008 to 12/2014 at the General Hospital of Fortaleza, Brazil. CS was used in 27 patients and not used in 15. The data was processed using the SPSS 20.0. The confidence level was 0.05. RESULTS There were no significant differences between the groups for the variables of age, sex, preoperative weight, postoperative blood drainage, and surgical time. There was a significant reduction in the intra-operative allogeneic transfusion in the case group compared to the control; there was no significant difference in the postoperative period. Adding the two periods together there was a significant difference with less allogeneic red blood cells (RBC) transfused in the CS group. The total cost of allogeneic RBC between the intra and postoperative groups was higher in the control group (P=0.01). Due to this difference ($350.00-$136.93) the cost was $213.07. The net savings were $213.07. Multiplying this by the 27 subjects, allogeneic RBC transfusion led to a cost reduction of $5,752.89 for the State. CONCLUSIONS The CS was effective in reducing allogeneic transfusion during surgery and in the total period that AIS patients underwent surgery it was also cost-effective.