Used a simultaneous presentation procedure to select quality reinforcers for 2 identical twin boys (aged 4 yrs) in a summer school program, who were developmentally delayed, noncompliant, and mute. Use of the simultaneous presentation procedure quickly and efficiently helped determine each boy's preferred reinforcer. This preferred reinforcer was then used in an instructional task. For both Ss, the percentage of compliance increased over baseline levels during both the simultaneous presentation and preferred reinforcer phases. However, increased compliance was associated almost exclusively with the selection of each S's preferred reinforcer. The simultaneous presentation procedure may enable trainers to use positive reinforcement instead of negative reinforcement procedures for individuals with disabilities, thus increasing the efficacy and the acceptability of training.