Background: Multiple large colonoscopy screening trials in North America and Europe have shown 25-30% overall prevalence of adenomatous polyps and 3-10% prevalence of advanced neoplasia [AN= adenoma≥1cm, presence of villous histology, high grade dysplasia or cancer] in individuals ≥50 years. Corresponding prospective data in an average-risk Middle Eastern population has not been reported. Aims: To determine the prevalence of AN at screening colonoscopy in a prospective Lebanese population, and to develop a risk prediction rule based on AN predictor risk factors. Methods: Nine-hundred eighty average-risk individuals were prospectively enrolled at time of screening colonoscopy. Comprehensive data collection included demographics, diet details, medications, tobacco and alcohol use, risk factors and pathology findings. Multivariate binary logistic regression was used to determine predictors of AN, and the model coefficients were used to calculate %Risk of (AN) in nomogram format. Results: The adenoma detection rate was 36.6%. AN was identified in 50 patients (5.1%) including 8 cancers (0.8%). Multivariate predictors of AN were age [Odds Ratio (95% confidence interval)= 1.036(1.00-1.07); p=0.048], increased body habitus category [overweight : 2.21 (0.98-5.00); obese ( ≥30 kg/m2): 3.54(1.48-8.50); p=0.018] relative to normal (≤25 kg/m2) BMI, tobacco [,40 pack-years: 2.01(1.01-4.01); ≥40 pack-years: 3.96(1.86-8.42); p=0.002], and daily red meat consumption [2.02(0.92-4.42)]. Nomograms of the predicted, incremental AN risk with daily red meat and tobacco use categories are shown in terms of age separately for normal, overweight and obese individuals [Figure]. Conclusions: Prevalence of adenomatous polyps and advanced neoplasia in an average-risk Lebanese population are similar to those reported from other parts of the world. Increasing age, cumulative heavy tobacco use, and body habitus are important risk factors for advanced neoplasia, with obesity being a particularly powerful predictor. A targeted approach to screening those at higher risk by colonoscopy may prove highly cost-effective in the prevention of colorectal cancer.