Background: The number of individuals aging with long-term spinal cord injury (SCI) is increasing. Still, there is limited knowledge about changes in secondary health conditions (SHCs) and activity limitations over time. Objectives: To determine changes in SHCs and activity limitations in older adults aging with long-term SCI over 6 years, and to investigate how changes in SHCs and activity limitations are associated with gender, age, and injury characteristics. Design: Longitudinal cohort study from the Swedish Aging with Spinal Cord Injury Study (SASCIS). Setting: Community settings, Sweden. Participants: From the initial 123 participants in the SASCIS: 78 individuals (32% women); mean age 68 years; mean time since injury 31 years; injury levels C1-L3, AIS A-D. Interventions: Not applicable Main Outcome Measure: Bowel and bladder function and problems, pain, spasticity, and the Spinal Cord Independence Measure (SCIM III). Results: Over 6 years, bowel-related problems increased (31% to 47%, p = .015) and the occurrence of constipation doubled to 24% (p = .013). There were increases in frequent urinary tract infections (10% to 26%, p = .004), use of indwelling urinary catheters (15% to 23%, p = .031), and other bladder-related problems (4% to 22%, p < .001). The occurrence of pain was high (85%), with no significant change. Spasticity increased from 41% to 62% (p < .001). Activity limitations increased (SCIM III total score mean 67 to 61, p < .001, with significant decreases in all subscales). The increase in bowel-related problems was greater in males, and the deterioration in self-care was greater in participants with longer time since injury and with traumatic injuries. Conclusions: These findings support the notion that SHCs and activity limitations increase over time in older adults aging with long-term SCI. The results can inform clinicians and call for a proactive, holistic approach in the long-term follow-up to support healthy and active aging.