Both ranitidine and metoclopramide produce neuropsychiatric side effects. Concomitant use of these drugs preoperatively may produce adverse behavioral and emotional changes. Therefore, in 123 unpremedicated patients undergoing tubal occlusion, behavior, cognitive function, and affect were studied before and after a 2-min intravenous injection of placebo (n= 30), ranitidine 50 mg (n= 32), metoclopramide 10 mg (n= 30), or both ranitidine 50 mg and metoclopramide 10 mg (n= 31). Cognitive function was evaluated by the responses to 11 statements devised to assess attitude toward anesthesia and surgery. Affect was assessed by the word chosen out of 11 word-pairs as best describing the feelings at the time. After ranitidine injection, one patient seemed restless and five seemed drowsy. The changes were associated with subjective feelings of agitation (P< 0.05) and restlessness (P< 0.05). After metoclopramide injection, 6 (20%) developed akathisia, 13 (43.3%) seemed restless, and 8 (26.7%) seemed drowsy. The changes were associated with subjective sensation of jumpiness (P< 0.01) and discomfort (P< 0.05). When both ranitidine and metoclopramide were injected, 10 (32.3%) developed akathisia, 4 (12.4%) seemed restless, and 11 (35.5%) seemed drowsy. The changes were associated with subjective feelings of agitation (P< 0.05), jumpiness (P< 0.05), restlessness (P< 0.01), and upset (P< 0.05). Akathisia, a side effect of metoclopramide, seemed to be more prominent when ranitidine was added.