Modular construction is an emerging construction technique due to its valuable benefits. This, on the other hand, faces a degree of uncertainty due to internal and external elements such as engineering, occupational, cultural, socioeconomic, and financial concerns that impact the project outcome mainly time and cost. Existing risk management research for conventional construction cannot be accurately applied to modular construction since modular construction is by nature different from conventional. This study is intended to identify primary risk factors associated with modular construction and conduct an assessment of their impacts on project cost and duration and compare them with those of conventional risks. After gathering a comprehensive list of risks in both construction methodologies, their probabilities and impacts on project cost and time were gathered through questionnaires and interviews. Based on the weighted average probabilities and impacts, risk categorization as per these three criteria was made. Moreover, comparison risk matrices were developed for different categories of risks.