Many randomized controlled trials (RCTs) perform additional analyses on specific subgroups within the defined study population. Subgroup analyses facilitate decision-making, as many surgeons strive to tailor treatment choices based on individual patient factors. This chapter seeks to familiarize surgeons with the critical appraisal of subgroup analyses in the literature. Specifically, we will examine (A) Are the results valid?, (B) What were the results?, and (C) Will the results help me in caring for my patients in my practice? This chapter illustrates the criteria for rigorous subgroup analyses in methodologically sound RCTs with an example clinical scenario and accompanying RCT.