Previous research has shown that self-injurious behavior (SIB) maintained by positive reinforcement may be reduced under differential-reinforcement-of-other-behavior (DRO) contingencies. In this study, we conducted an analysis of the reinforcement and extinction components of DRO while treating the self-injury of 3 women with developmental disabilities. A functional analysis revealed that each subject's SIB was maintained by positive reinforcement in the form of attention. Subsequent reinforcer assessments identified preferred and nonpreferred stimuli for later use in conjunction with DRO. Results showed high rates of SIB for all 3 subjects during baseline, which persisted when DRO was implemented without the relevant extinction component (withholding of attention for SIB) for 2 of the subjects. Low rates of SIB were observed for all subjects when DRO plus extinction was implemented or when extinction was implemented alone, suggesting that extinction may be a critical component of DRO schedules.