Background: Rehabilitation is a type of treatment that focuses on improving a person's physical, social, cognitive, and emotional functioning. Currently, there is a significant unmet need for rehabilitation. Despite the expansion of rehabilitation services in Ethiopia, little is known about its utilization and associated factors.Objective: This study aimed to assess the utilization of rehabilitation services and associated factors among adults with cancer diagnoses at Hawassa Comprehensive Specialized Hospital, Ethiopia. Methods: An institutional-based cross-sectional study was employed among 325 participants selected using a systematic sampling technique. Data were collected using a pre-tested, interviewer-administered questionnaire and a review of medical records. Participants were considered as utilized if they attended at least one cancer rehabilitation service at the hospital in the last 1 year. The data were entered into EpiData version 4.6 and exported to Statistical Package for Social Science Version 23 for analysis. Binary logistic regression analysis was used to identify factors associated with the utilization of rehabilitation services. Variables with a P-value of < 0.05 were considered statistically significant. Results: Utilization of rehabilitation service among adults with cancer diagnoses in the last 1 year were found to be 33.