Thirty‐seven patients undergoing elective abdominal surgery (excluding gastric operations) received either ranitidine 300 mg or placebo orally at 10 p. m. in the evening preceding surgery in a double‐blind randomised study. The mean time interval between this oral premedication and induction of anaesthesia was 12 h. When compared to placebo, ranitidine decreased significantly (P<0.05) the amount of gastric juice, and none of the ranitidine‐treated patients had an increased risk of acid pulmonary aspiration (pH below 2.5 and volume over 25 ml), while four patients in the control group had an increased risk (21%). The mean ranitidine blood level was 237 ng/ml at the time of induction of anaesthesia. It is concluded that in elective abdominal surgery ranitidine included in the premedication is likely to decrease the risk for acid pulmonary aspir