Background: Peripheral venous cannulation is the commonest method used for intravenous therapy. There are numerous well recognized indications such as intravenous fluids, limited parenteral nutrition, blood and blood products, drug administration (continuous or intermittent). The aim of the present study is 3-folds: the first is to assess nurse's knowledge and practice regarding intravenous therapy, the second is to design nursing protocol for nurses about intravenous therapy and the third is to evaluate the effect of implementing the designed nursing protocol on nurse's knowledge and practice regarding intravenous therapy. Hypotheses: Three hypotheses were formulated: (1) the post mean knowledge scores of nurses who will be exposed to designed nursing protocol will be higher than their pre mean knowledge scores. (2) The post mean practice score of nurses who will be exposed to a designed nursing protocol will be higher than their pre mean practice scores. (3) A positive relationship will exist between knowledge and practice score obtained by nurses receiving the designed nursing protocol. Research design: Aquasi-experimental research design was utilized in this study on a convenient sample of 55 nurses. The study will be conducted in general medical departments (B and C) and blood diseases unite of Assiut university hospital. Tools: utilize for data collection were a) Questionnaire sheet. b) Observation checklist sheet. c) Construction of designed nursing protocol. Results: The first and the second hypotheses were supported as a good improvement in the mean knowledge & practice scores were found after the implementing of designed nursing protocol. The third hypothesis was supported as a negative relationship was found between nurse's knowledge and practice scores immediately after application of the designed nursing protocol. Conclusion: implementing the designed nursing protocol on nurse's knowledge and practice regarding intravenous therapy shows a significant improvement in nurses' knowledge and practice. Recommendation: Continued nursing education and in-service training programs should be well organized within Assiut University Hospital.