Introduction: acute mechanical intestinal obstruction (IO) is one of the leading causes of surgical admissions in most emergency departments worldwide. The causes of IO vary significantly depending on geographical location. The aim of this study was to identify the etiology, management and outcomes of patients with acute mechanical IO presenting in south-western Kenya. Methods: a 4 year (November 2009–October 2013) retrospective review of all adult patients admitted with acute mechanical IO at Tenwek Hospital in Bomet, Kenya. Results: a total of 303 male and 142 female patients, presented with acute mechanical IO during the study period. Mean patient age was 40.6 years (range 17-91), with peak incidence in those aged 31-40 years. The foremost signs and symptoms were abdominal pain (89.4%), abdominal tenderness (81.6%), vomiting (78%), abdominal distension (65.4%) and constipation (50.8%). Sigmoid volvulus (25.6%), adhesions (23.1%), small bowel volvulus (21.3%), and ileo-sigmoid knotting (8.5%) were the leading causes of IO. Laparotomy was undertaken in 361 (81.1%) cases, with bowel gangrene noted in 112 (30.4%). The overall morbidity and mortality rates were 15% and 4.5% respectively. Patients with gangrenous bowel at laparotomy had a higher morbidity rate (22.3% vs 9.6%, P=.001), a higher mortality rate (9.8% vs 3.2%, P=.02) and a longer duration of stay (9.9 days vs 7.6 days, P=.0001) compared to those with viable bowel. Conclusion: the most common causes of IO in this study were sigmoid volvulus, adhesions, small bowel volvulus and ileo-sigmoid knotting. Presence of bowel gangrene was associated with higher morbidity and mortality rates.