BACKGROUND: The purpose of this clinical study was to evaluate the Incentive Spirometry (IS) and Deep Breathing Exercises (DBE) to prevent postoperative pulmonary complications after abdominal surgery in patients over 60 years of age. METHODS: We prospectively randomized 90 patients into 1 of 3 groups: the control group (30 patients) received no respiratory treatment, the IS group (30 patients) was treated with incentive spirometry 4 times daily and DBE group (30 patients) carried out deep breathing exercises under supervision for 15 min 4 times daily. ABGA was taken at ward, PR (preop.room), RR (recovery room), POD1 day and POD2 day. Roentgenographic changes observed at 24 h. and 48 h. after surgery. Pulmonary complications were defined as the development of 3 or more of 6 new findings: cough, sputum, dyspnea, chest discomfort, temperature greater than 38oC, pulse rate more than 100 beats/min. RESULTS: PaO2 in the DBE group and IS group at PR were significantly increased than the values at ward, and the values of the PaO2 in the DBE group at RR and POD1 day, and those of IS group at PR and POD2 day were significant higher than those of the control group (p<0.05). The frequency of development of pulmonary complications (43.3% in the control group, 20% in the DBE group, 20% in the IS group) and roentgenographic changes were comparable in the 3 groups (26.7%, 16.7%, 20% respectively). The DBE group showed the different incidence of postoperative pulmonary complications between upper and lower abdominal surgery (upper: lower= 35.7: 6.3%). CONCLUSIONS: We concluded that DBE and IS were effective in preventing postoperative pulmonary complications after abdominal surgery and lower abdominal surgery causes lesser postoperative pulmonary complications than upper abdominal surgery.