Nigerian Construction Industry is suffering from the misunderstanding of risk management This research seeks to investigate the perceptions of contractors and consultants in assessing the most significant risks factors (in terms of their severity and allocation), and the effective remedial actions utilized in Nigerian building projects. A survey was conducted to collect data from practitioners (contractors and consultants) in the industry over a total of 60 potential risk factors identified and categorised into nine (9) groups.'SPSS' version 20 was used to get mean score values representing the current views of the practitioners in the zone. Descriptive analysis was adopted for data analysis. The findings showed that Contractors perceived 'payment delays as the most significant risk factor while, the consultants viewed 'awarding the design to unqualified designers' as the riskiest and significant factor. And that 'referring to similar projects' and 'use of updated project info. to get accurate data' were perceived by the practitioners as the most effective risk preventive methods. Nigerian Practitioners will better understand the critical risk factors and their impacts on Projects.