This study will use a prospective randomized control group design to examine the effects of a six-week yoga-based stress reduction intervention on perceived stress in caregivers of allogeneic HSCT patients. Subjects will be accrued to this protocol if they are a caregiver of an individual undergoing allogeneic HSCT at the Clinical Center, NIH, are greater than or equal to 18 years old, able to read English, stand and sit unassisted, raise arms over head without pain, and able to comprehend the investigational nature of the study. A sample of at least 78 caregivers is needed to adequately evaluate the effectiveness of the intervention.