Gastrointestinal (GI) bleeding is a potentially life-threatening condition that requires prompt and appropriate management. Aim of this study was to examine the effect of implementing nursing guidelines on nurses' knowledge and practice for patient with gastrointestinal bleeding during the first 24 hours. Materials and Method: Quasi experimental design was utilized. Study subjects: All available nurses were included (40) nurses. Two tools were used: including demographic characteristics of the studied nurses, nurses' knowledge and practice about nursing management of patients with GI bleeding. Results: before implementing the guidelines 11.1% of the studied nurses had satisfactory level of knowledge, and 2.8% of them had satisfactory level of practice, while after implementing the guidelines 97.2% of them had satisfactory level of knowledge and 86.1% had satisfactory level of practice. Conclusions: Nursing management intervention guidelines significantly improved nurses' performance for patients with GI bleeding.