Objective: To analyze the incidence, risk factors, and trends of long- term secondary medical complications in individuals with traumatic spinal cord injury. Design: Data were reviewed from the National SCI Statistical Center on annual evaluations performed at 1, 2, 5, 10, 15, and 20 years after injury on patients injured between 1973 and 1998. Setting: Multicenter Regional SCI Model Systems. Main Outcome Measures: Secondary medical complications at annual follow-up years, including pneumonia/atelectasis, autonomic dysreflexia, deep venous thrombosis, pulmonary embolism, pressure ulcers, fractures, and renal calculi. Results: Pressure ulcers were the most frequent secondary medical complications in all years, and individuals at significant (p < .05) risk included those with complete injuries (years 1, 2, 5, 10), younger age (year 2), concomitant pneumonia/atelectasis (year 1, 2, 5), and violent injury (years 1, 2, 5, 10). The incidence of pneumonia/atelectasis was 3.4% between rehabilitation discharge and year-1 follow-up with those most significantly at risk being older than 60 years (years 1, 2, 5, 10) and tetraplegia-complete (years 1, 2). One-year incidence of deep venous thrombosis was 2.1% with a significant decline seen at year 2 (1.2%), and individuals most significantly (p < .001) at risk were those with complete injuries (year 1). The incidence of calculi (kidney and/or ureter) was 1.5% at 1-year follow-up and 1.9% at 5 years and was more frequent in patients with complete tetraplegia. Intermittent catheterization was the most common method of bladder management among patients with paraplegia but became less common at later postinjury visits. Conclusions: Pressure ulcers, autonomic dysreflexia, and pneumonia/atelectasis were the most common long- term secondary medical complications found at annual follow-ups. Risk factors included complete injury, tetraplegia, older age, concomitant illness, and violent injury.