A modification of the technique of Harrington instrumentation for idiopathic scoliosis utilizes segmental spinous process wiring. The purpose of this study is to contrast and compare two populations of surgically treated patients with idiopathic scoliosis: one group with a single Harrington distraction rod and the other group with the addition of spinous process wiring. Of 252 consecutive patients between 1971 and 1987, 215 were retrievable, with an average clinical follow-up of 2.2 years. Curves were analyzed by location and patient age. Patients treated with spinous process wires were braced, those without were casted. No significant difference in terms of percent correction with time was evident between the two treatment groups. The complication rate (11.0%) and pseudarthrosis rate (4.0%) were the same in both wired and standard groups. The more rigid adult curves resulted in less correction and greater complications than adolescent curves. Spinous process wiring seemed to protect against upper hook cut-out. There were no deaths or paraplegias. Patients surgically treated with the wire modification enjoyed greater comfort with the removable brace, and curve correction was equal to that obtained in patients treated with the standard technique and post-op casting.