According to relational frame theory (RFT), temporal relational responding is key to important repertoires, including sequencing, ordering, planning, and time understanding. Previous studies have taught several other varieties of relational responding (e.g., comparison, deictics) but relatively little work has been done in the case of temporal relational responding. The present study aimed to assess existing temporal relational responding skills in three autistic adolescents and to evaluate the efficacy of an RFT-based multiple exemplar training (MET) procedure to teach nonarbitrary (physically based) temporal relations, which constitute an important foundation for derived temporal relations. Results indicated that all participants achieved mastery (100% across two sessions) for nonarbitrary temporal relations following MET. During post-training phases, each of the participants maintained performance 2 and 4 weeks later, and the skill was extended to two novel data sets (100% accuracy).