Prior to the issuance of the final rule for side impact protection, the National Highway Traffic Safety Administration initiated a research program for evaluation of three side impact dummies for potential use in side impact testing per the regulation. The test devices evaluated included the NHTSA developed SID, the EUROSID-l developed under the sponsorship of the European Experimental Vehicle Committee and the BIOSID which was designed and developed under the auspices of the Society of Automotive Engineers’, Biomechanics and Simulations Subcommittee. The test program included dummy performance verification testing, sled tests to evaluate the capability of the dummies to discriminate impact surfaces of various crush strength characteristics and a limited number of production passenger car tests. Assessment of the comparative performance of the dummies was made on the basis of the injury criteria specified in the final side impact rule, namely, the Thoracic Trauma Index and pelvic accelerations. Repeatability performance and biofidelity of the dummies were also evaluated. This paper describes the tests conducted and the results in detail, comparing the performance of the three dummies.