Tethered cord syndrome (TCS) is characterized by progressive spinal cord degeneration secondary to congenital spinal dysraphism. The associated accompanying physical inactivity and musculoskeletal deformities have raised interest in the growth profile of adult TCS patients. However, few previous studies have investigated the growth profile of adult TCS patients. We retrospectively reviewed the demographic data and medical records of 20-year-old Korean conscription examinees who were registered between April 2004 and September 2019. In total, 151 examinees with a diagnosis of TCS were enrolled. The height, weight, and body mass index (BMI) of 300 randomly selected examinees were compared to the TCS group. Obesity was defined by the World Health Organization and Asian-Pacific criteria for BMI and compared between the groups. Growth profile differences according to tethering location and musculoskeletal deformities were analyzed in both groups. The mean height, weight, and BMI values of the TCS group were lower than those of the control group. The TCS group had a lower proportion of obese and overweight individuals, and a higher proportion of underweight individuals, according to both BMI criteria. The tethering level was not associated with the degree of obesity in the tethered group. The mean height, weight, and BMI were lower in the tethered group regardless of the existence of musculoskeletal deformity. Enrollees with a history of TCS were smaller than controls of the same age. Monitoring of health behaviors, including nutrition, diet, and exercise, is warranted for TCS patients.