Allogeneic hematopoietic cell transplantation (alloHCT) is a vital therapy for various hematologic diseases, though it demands high physiological resilience. Frailty, a syndrome impacting the body's ability to withstand stress, affects outcomes of alloHCT across all ages. This study examines the relationship between frailty and peri-transplant activity and sleep patterns using Fitbit devices. In this pilot study, adults scheduled for their first myeloablative alloHCT at the University of Minnesota from June 2022 to January 2023 were included if they had a compatible device for the Fitbit app. Participants were monitored for activity and sleep from admission to day +30 post-transplant. Frailty was assessed pre-transplant using Fried Phenotype criteria. Data were analyzed for activity and sleep patterns differences among not frail, pre-frail, and frail groups. Nine patients provided sufficient data for analysis, showing significant variances in activity levels and sleep patterns across frailty categories. Not frail patients exhibited significantly higher daily steps and active minutes than pre-frail and frail patients. Not frail patients also had the highest amount of restorative deep and rapid eye movement sleep. Due to Fitbit methodology and likely frequent interruptions, 28% of the days in the first month post-transplant had a recorded sleep time of 0 minutes. Although our sample size was small, our findings underscore the importance of frailty in influencing activity and sleep patterns among alloHCT recipients.