Objectives: To assess causes, signs & symptoms of mechanical obstruction of the small bowel. Background: Mechanical obstruction of the small bowel is a common clinical and surgical condition, often presenting with signs and symptoms like those seen in other acute abdominal disorders controversy remains as to which patients with small bowel obstruction need immediate surgical intervention and which may be managed conservatively. Patients and Methods: A prospective study to assess incidence, causes, signs, and symptoms among ninety-two patients undergoing surgeries due to mechanical small bowel obstruction in Al-Yarmouk Teaching Hospital. In a period between October 2016 and October 2017 patients have divided into two groups 1 patients had surgery during the first 24hr from the start of signs & symptoms and a group of 2 patients had surgery after 24hr since the beginning of signs & symptoms. Results: Among ninety-two patients included in this study the result was 54 male (58.7%) and 38 female (41.3%). Patients with the previous scar were 62 cases (67.4%). The most common causes of MOSB were adhesions (63%), obstructed hernia (29.3%) most common type was inguinal hernia (16.3%), tumors (4.34%) and other causes were Crohn’s, bezoar, and intussuscept. Conclusion: Mechanical obstruction. The small bowel is a severe condition and moderately common in cases of acute abdomen adhesions were the commonest cause of MOSB also a high incidence of strangulation was seen in obstructed hernia, and patients generally present with abdominal pain, nausea and emesis, abdominal distension, and progressive obstipation, the clinical finding of high fever. Localized or generalized severe abdominal tenderness, rebound tenderness, severe leukocytosis, or metabolic changes suggest possible complications of bowel necrosis, perforation, or generalized peritonitis. MSBO is usually suggested by plain abdominal radiographs and confirmed by a CT scan.