Background: With respect to high prevalence of chronic pain in the elderly, identifying factors influencing on its management process is very important. Objectives: The present study aimed to understand this management process and its setbacks in the elderly. Materials and Methods: The grounded theory approach using unstructured interviews and observation of participants were the main methods for data collection. Study participants consisted of 30 old people with chronic pain, 3 relatives, and 29 health care providers selected with purposive and theoretical sampling methods in Ahvaz. Sampling was continued until data saturation reached. Data analysis was performed concurrently with data gathering based on Strauss and Corbin's proposed method. Data rigor (trustworthiness) was confirmed by Lincoln and Gubba's approach. Results: Vulnerability was one of major themes extracted as parts of a Grounded Theory study results, which composed of three categories: functional impairment, disability, and limitations. Many participants had functional impairment in their mood and emotional, social, and psychological aspects and encountered a series of disabilities for doing their daily activities. Moreover, they had limitations in physical as well as environmental aspects, all of them influenced their pain management. Conclusions: Chronic pain in the elderly has often been assessed and treated inadequately; therefore, attention to their problems and limitations may be useful in developing a comprehensive caring program and managing effectively their chronic pain.