Background: Cancer is a chronic condition associated with a substantial symptom burden, which can impair recovery after treatment. Investigating interventions with potential to improve self-reported disease and/or treatment effects-known as patient-reported outcomes (PROs)-is paramount to inform cancer care. The objective of this study was to evaluate the effects of a yoga therapy (YT) intervention on key PROs (ie, cancer-related fatigue, anxiety, cognitive function, depression, stress, quality of life [QoL]) among adults after treatment for cancer., Methods: Data from 20 adults ( M age = 55.74 years, 85% female; M time since diagnosis = 2.83 years) who had completed treatment for cancer were analyzed for this study. In this single-subject exploratory experimental study, the YT intervention comprised a 1:1 YT session (ie, 1 participant with 1 yoga therapist) followed by 6 weekly small (ie, 2-3 participants) group YT sessions. Group sessions were facilitated by the same yoga therapist who delivered participants' 1:1 session to ensure an in-depth personalized approach. PROs were assessed before (ie, pre-intervention) and after the 1:1 YT session (ie, during the intervention), as well as after the last group YT session (ie, post-intervention). Hierarchical linear modeling was used to analyze the data., Results: Participants showed improvements in cancer-related fatigue, state anxiety, trait anxiety, perceived cognitive impairments, impacts of perceived cognitive impairments on QoL, and 1 dimension of QoL (ie, functional wellbeing) over time. Notably, cancer-related fatigue and state anxiety increased immediately after the 1:1 session, but showed greater improvements over time afterward (ie, during the intervention phase). No changes were observed for the remaining PROs., Conclusion: Although results require confirmation in future trials, this study highlights the importance of continuing to investigate YT as an intervention to enhance important PROs (ie, cancer-related fatigue and state anxiety) after treatment for cancer. More research is needed to identify additional beneficial effects and factors that influence participants' responses to 1:1 and group YT (ie, moderators and mediators)., Registration Number: ISRCTN64763228., Date of Registration: December 12, 2021. This trial was registered retrospectively., Url of Trial Registry Record: https://www.isrctn.com/ISRCTN64763228., Published Protocol: Brunet, J., Wurz, A., Hussien, J., Pitman, A., Conte, E., Ennis, J. K., . . . & Seely, D. (2022). Exploring the Effects of Yoga Therapy on Heart Rate Variability and Patient-Reported Outcomes After Cancer Treatment: A Study Protocol. Integrative Cancer Therapies , 21 , 15347354221075576., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.