Purpose: Research has shown that young children with speech sound disorders may have weaknesses in phonological processing. However, such skills have not been thoroughly examined in adolescents with residual speech sound errors. Therefore, this study compared the phonological processing abilities of adolescents with residual speech sound errors to those of normally speaking peers. Method: Two nonword repetition tasks, multisyllabic word repetition, spoonerisms, phoneme reversals, and an elision task were used to compare the phonological processing skills of 10-14-year-olds with residual speech sound errors that include rhotic phonemes (RE, n = 13) to those of normally speaking (NS, n = 14) adolescents of similar age and receptive vocabulary abilities. Results: The 2 groups were found to differ on 5 of the 6 phonological processing tasks. Discriminant analysis showed that 85% of the participants could be correctly classified into the RE and NS groups based solely on phonological processing skills. Conclusion: The possible nature of the phonological processing impairment is discussed in the context of current theoretical understanding. It is recommended that when planning assessment and intervention for adolescents with residual speech sound errors, clinicians be cognizant of the fact that the adolescents may also have weaknesses in phonological processing. (Contains 5 tables and 1 figure.)