An association between spinal kyphosis and gastroesophageal reflux disease (GERD) was reported in recent years. However, it remains unclear whether spinal kyphosis affects gastric motility. We evaluated the changes in myoelectrical activity measured by electrogastrography (EGG) in elderly osteoporosis patients. A total of 18 patients scheduled for the treatment of osteoporosis were included in this study. They were analyzed by recording EGG to assess myoelectrical activity and heart rate variability (HRV) to evaluate the autonomic nervous system function before and after meals. Dominant power (DP) representing the strength of gastric electrical activity and dominant frequency (DF) representing its frequency were analyzed in blocks with a 5-minute duration. We divided the patients into 2 groups, thoracolumbar kyphosis (TLK) and non-TLK groups, and compared them. There were no significant differences between the 2 groups in background data. In the non-TLK group, DPs post 0-5 min were significantly higher than those during pre 5-0 min in channels 1 and 3 (P < 0.05 and P < 0.01). DF deviation in the TLK group was significantly higher than that in the non-TLK group at 10 to 15 postprandial minutes (P < 0.05). Low frequency/high frequency activity measured by HRV, reflecting the activity of the sympathetic nervous system, in the TLK group was significantly lower than that in the non-TLK group while eating (P < 0.01). The EGG of patients with spinal kyphotic deformity showed a similar change to that of patients with GERD; the spinal kyphotic deformity itself may affect gastric electrical activity.