Abstract: A study to examine the effects of pre- information ( what a Nurse learns about a patient before they meet) on clinical inference and Nursing actions, in a simulated Nurse- Patient situation. It was hypothesised that the nature of the pre-information will influence the way the patient is perceived and the resulting Nursing actions. The research was conducted in an obstetrical setting. There were 55 subjects within three groups. Two groups comprised student midwives and the third group was of second year comprehensive Nursing students near completion of clinical experience in maternal and child health nursing. A 5 minute videotape sequence of a role played post natal patient was made for use in the research. All subjects were given the same initial pre-information, viewed the videotape and gave written description of what they saw on the videotape and their response ( as the Nurse in the situation). This data provided a base line for each subject. Subject were then given additional pre-information concerning the patient's physical condition, her baby's condition or formed part of the control group ( receiving no additional information) The procedure was repeated. These responses were then compared with the base line for each subject. Responses were coded by means of content analysis. Group data was analysed using multivariate one way analysis of variance graphical display. The results indicated support of the hypothesis that the nature of the pre-information does influence the way in which a Nurse perceives a patient and resulting Nursing actions. Implications of these findings for Nurses are discussed