Aim The purpose of the present study was to evaluate and compare clinical outcomes in patients aged >65 years and <65 years who have undergone surgery for infectious spondylitis, and to identify any prognostic factors. Methods We reviewed 60 consecutive patients treated surgically for infectious spondylitis. We reviewed patients’ medical records especially focusing on comorbidities, preoperative serum albumin levels, postoperative complications and control of infection on follow up. Statistical analysis was carried out to determine whether these various factors affected clinical outcomes. Results Postoperative complication rates (P = 0.764) and infection control rates (P = 0.275) were not significantly different between the two groups. Univariate analysis did not show a correlation between age and clinical outcome, whereas body mass index (BMI; P = 0.04), Charlson Comorbidity Index (CCI; P = 0.017), American Society of Anesthesiologists (ASA) grade (P = 0.006) and serum albumin (P = 0.003) were associated with overall postoperative complications. BMI (P = 0.002) and CCI (P = 0.000) were also associated with postoperative fatalities. The χ2‐test for trend also showed that CCI (P = 0.018), ASA grade (P = 0.007) and low serum albumin (<3.5 mg/dL; P = 0.004) were associated with postoperative complications. Logistic regression analysis showed that ASA grade (P = 0.034) and BMI (P = 0.044) were related to overall postoperative complications. Receiver operating characteristic curve analysis using ASA grade and BMI to predict major postoperative complications and fatality showed an area under the curve value of 0.793 (P = 0.001) and 0.942 (p=0.002), respectively. Conclusions BMI, ASA grade, CCI scores and serum albumin levels, rather than age, might be useful in predicting clinical outcome in surgery for infectious spondylitis in elderly patients. Geriatr Gerontol Int 2017; 17: 984–990.