The word psychosis generally elicits the emotions of fear. Psychosis refers to the mental state of experiencing the same things and wonders why others are not reacting in a similar manner. The overall goal of nursing care is to help the patient recognize the psychosis and develop strategies to manage the symptoms. The mutual confusion created by psychosis creates challenges when providing nursing care to patients with schizophrenia and other psychotic disorders. This study has been conducted to develop, implement and evaluate the effect of a nursing intervention protocol for nurses working with psychotic patient through assessing the knowledge of the nurses caring for psychiatric patients, observe the performance of the nurses while caring for the psychotic patients. The study hypotheses: nursing intervention protocol given to nurses caring for psychotic patients will lead to increase their knowledge and improve their performance of care. The study was conducted in psychiatric mental health hospital at Benha city. The study subject was comprised all available nurses working in psychiatric hospital (100).The data was collected from September, 2008 to February, 2009. The tools of data collection: a questionnaire sheet comprised socio-demographic characteristics of nurses, questions to assess nurse's knowledge about nature of psychotic disorders, treatment, nursing care, relapse and patient rehabilitation and observation checklist to assess nurse's behavior and performance toward psychotic patients. The result of the study there was a significant better improvement of all items of knowledge scores and performance post program implementation than pre and there was significant positive correlation between nurse's knowledge and performance pre and post program implementation. The study recommended that the undergraduate diploma nurse's curriculum should be connected closely with the practical time.