This paper presents an empirical investigation to study the effects of different factors influencing on accomplishment of projects in Iranian oil industry. The proposed study designs a questionnaire consists of 50 questions in Likert scale with seven factors including sanctions, economy, scheduling, contractor management weaknesses, cultural/social, force majeure and contractee. The study considers the effects of these factors in three categories; namely risk of project scheduling, risk in project cost and risk in management weakness. Using structural equation modeling, the study confirms that all three factors influence on the success of oil projects. In other words, The results have indicated that budgeting as well as cost accounting is the most important factor in accomplishment of oil projects followed by weakness in management and having an appropriate scheduling.